Created by William Kapke
kangax's compat-table applied only to Node.js
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Node.js ES2015 Support

24.0.0
(these versions have identical results)
nightly v8 13.0.245.25-node.12
Nightly!99% complete99% complete 		23.10.0
(these versions have identical results)
23.10.0 v8 12.9.202.28-node.13
23.9.0 v8 12.9.202.28-node.13
23.8.0 v8 12.9.202.28-node.13
23.7.0 v8 12.9.202.28-node.12
23.6.1 v8 12.9.202.28-node.12
23.6.0 v8 12.9.202.28-node.12
23.5.0 v8 12.9.202.28-node.12
23.4.0 v8 12.9.202.28-node.11
23.3.0 v8 12.9.202.28-node.11
99% complete99% complete 		23.2.0
(these versions have identical results)
23.2.0 v8 12.9.202.28-node.11
23.1.0 v8 12.9.202.28-node.11
23.0.0 v8 12.9.202.26-node.10
99% complete99% complete 		22.14.0
(these versions have identical results)
22.14.0 v8 12.4.254.21-node.22
22.13.1 v8 12.4.254.21-node.22
22.13.0 v8 12.4.254.21-node.22
22.12.0 v8 12.4.254.21-node.21
99% complete99% complete 		22.11.0
(these versions have identical results)
22.11.0 v8 12.4.254.21-node.21
22.10.0 v8 12.4.254.21-node.21
22.9.0 v8 12.4.254.21-node.19
22.8.0 v8 12.4.254.21-node.19
22.7.0 v8 12.4.254.21-node.18
22.6.0 v8 12.4.254.21-node.18
22.5.1 v8 12.4.254.21-node.16
22.5.0 v8 12.4.254.21-node.16
22.4.1 v8 12.4.254.21-node.15
22.4.0 v8 12.4.254.21-node.15
22.3.0 v8 12.4.254.20-node.13
22.2.0 v8 12.4.254.14-node.12
22.1.0 v8 12.4.254.14-node.11
22.0.0 v8 12.4.254.14-node.10
99% complete99% complete 		21.7.3
(these versions have identical results)
21.7.3 v8 11.8.172.17-node.20
21.7.2 v8 11.8.172.17-node.20
21.7.1 v8 11.8.172.17-node.20
21.7.0 v8 11.8.172.17-node.20
21.6.2 v8 11.8.172.17-node.19
21.6.1 v8 11.8.172.17-node.19
21.6.0 v8 11.8.172.17-node.19
21.5.0 v8 11.8.172.17-node.18
21.4.0 v8 11.8.172.17-node.17
21.3.0 v8 11.8.172.17-node.17
99% complete99% complete 		21.2.0
(these versions have identical results)
21.2.0 v8 11.8.172.17-node.15
21.1.0 v8 11.8.172.15-node.14
21.0.0 v8 11.8.172.13-node.12
99% complete99% complete 		20.19.0
(these versions have identical results)
20.19.0 v8 11.3.244.8-node.26
99% complete99% complete 		20.18.3
(these versions have identical results)
20.18.3 v8 11.3.244.8-node.25
20.18.2 v8 11.3.244.8-node.23
20.18.1 v8 11.3.244.8-node.23
20.18.0 v8 11.3.244.8-node.23
20.17.0 v8 11.3.244.8-node.23
20.16.0 v8 11.3.244.8-node.23
20.15.1 v8 11.3.244.8-node.23
20.15.0 v8 11.3.244.8-node.23
20.14.0 v8 11.3.244.8-node.23
20.13.1 v8 11.3.244.8-node.20
20.13.0 v8 11.3.244.8-node.20
20.12.2 v8 11.3.244.8-node.19
20.12.1 v8 11.3.244.8-node.19
20.12.0 v8 11.3.244.8-node.19
99% complete99% complete 		20.11.1
(these versions have identical results)
20.11.1 v8 11.3.244.8-node.17
20.11.0 v8 11.3.244.8-node.17
20.10.0 v8 11.3.244.8-node.25
20.9.0 v8 11.3.244.8-node.16
20.8.1 v8 11.3.244.8-node.16
20.8.0 v8 11.3.244.8-node.16
20.7.0 v8 11.3.244.8-node.15
20.6.1 v8 11.3.244.8-node.14
20.6.0 v8 11.3.244.8-node.14
20.5.1 v8 11.3.244.8-node.10
20.5.0 v8 11.3.244.8-node.10
20.4.0 v8 11.3.244.8-node.10
20.3.1 v8 11.3.244.8-node.9
20.3.0 v8 11.3.244.8-node.9
20.2.0 v8 11.3.244.8-node.9
20.1.0 v8 11.3.244.8-node.6
20.0.0 v8 11.3.244.4-node.3
99% complete99% complete 		19.9.0
(these versions have identical results)
19.9.0 v8 10.8.168.25-node.16
19.8.1 v8 10.8.168.25-node.12
19.8.0 v8 10.8.168.25-node.12
19.7.0 v8 10.8.168.25-node.11
19.6.1 v8 10.8.168.25-node.11
19.6.0 v8 10.8.168.25-node.11
19.5.0 v8 10.8.168.25-node.11
19.4.0 v8 10.8.168.25-node.11
19.3.0 v8 10.8.168.21-node.8
19.2.0 v8 10.8.168.20-node.8
99% complete99% complete 		19.1.0
(these versions have identical results)
19.1.0 v8 10.7.193.20-node.19
99% complete99% complete 		19.0.1
(these versions have identical results)
19.0.1 v8 10.7.193.13-node.16
19.0.0 v8 10.7.193.13-node.16
99% complete99% complete 		18.20.7
(these versions have identical results)
18.20.7 v8 10.2.154.26-node.39
18.20.6 v8 10.2.154.26-node.37
18.20.5 v8 10.2.154.26-node.37
18.20.4 v8 10.2.154.26-node.37
18.20.3 v8 10.2.154.26-node.37
18.20.2 v8 10.2.154.26-node.36
18.20.1 v8 10.2.154.26-node.36
18.20.0 v8 10.2.154.26-node.36
99% complete99% complete 		18.19.1
(these versions have identical results)
18.19.1 v8 10.2.154.26-node.28
18.19.0 v8 10.2.154.26-node.28
18.18.2 v8 10.2.154.26-node.26
18.18.1 v8 10.2.154.26-node.26
18.18.0 v8 10.2.154.26-node.26
18.17.1 v8 10.2.154.26-node.26
18.17.0 v8 10.2.154.26-node.26
18.16.1 v8 10.2.154.26-node.26
18.16.0 v8 10.2.154.26-node.26
18.15.0 v8 10.2.154.26-node.25
18.14.2 v8 10.2.154.26-node.22
18.14.1 v8 10.2.154.23-node.22
18.14.0 v8 10.2.154.23-node.22
18.13.0 v8 10.2.154.23-node.21
99% complete99% complete 		18.12.1
(these versions have identical results)
18.12.1 v8 10.2.154.15-node.12
18.12.0 v8 10.2.154.15-node.12
18.11.0 v8 10.2.154.15-node.12
18.10.0 v8 10.2.154.15-node.12
18.9.1 v8 10.2.154.15-node.12
18.9.0 v8 10.2.154.15-node.12
18.8.0 v8 10.2.154.13-node.11
18.7.0 v8 10.2.154.13-node.9
18.6.0 v8 10.2.154.13-node.8
18.5.0 v8 10.2.154.4-node.8
18.4.0 v8 10.2.154.4-node.8
18.3.0 v8 10.2.154.4-node.8
18.2.0 v8 10.1.124.8-node.13
18.1.0 v8 10.1.124.8-node.13
18.0.0 v8 10.1.124.8-node.13
99% complete99% complete 		17.9.1
(these versions have identical results)
17.9.1 v8 9.6.180.15-node.16
17.9.0 v8 9.6.180.15-node.16
17.8.0 v8 9.6.180.15-node.16
17.7.2 v8 9.6.180.15-node.15
17.7.1 v8 9.6.180.15-node.15
17.7.0 v8 9.6.180.15-node.15
17.6.0 v8 9.6.180.15-node.13
17.5.0 v8 9.6.180.15-node.13
17.4.0 v8 9.6.180.15-node.13
17.3.1 v8 9.6.180.15-node.12
17.3.0 v8 9.6.180.15-node.12
17.2.0 v8 9.6.180.14-node.12
99% complete99% complete 		17.1.0
(these versions have identical results)
17.1.0 v8 9.5.172.25-node.13
17.0.1 v8 9.5.172.21-node.12
17.0.0 v8 9.5.172.21-node.12
99% complete99% complete 		16.20.2
(these versions have identical results)
16.20.2 v8 9.4.146.26-node.26
16.20.1 v8 9.4.146.26-node.26
16.20.0 v8 9.4.146.26-node.26
16.19.1 v8 9.4.146.26-node.24
16.19.0 v8 9.4.146.26-node.24
16.18.1 v8 9.4.146.26-node.22
16.18.0 v8 9.4.146.26-node.22
16.17.1 v8 9.4.146.26-node.22
16.17.0 v8 9.4.146.26-node.22
16.16.0 v8 9.4.146.24-node.21
16.15.1 v8 9.4.146.24-node.21
16.15.0 v8 9.4.146.24-node.20
16.14.2 v8 9.4.146.24-node.20
16.14.1 v8 9.4.146.24-node.20
16.14.0 v8 9.4.146.24-node.20
99% complete99% complete 		16.13.2
(these versions have identical results)
16.13.2 v8 9.4.146.24-node.14
16.13.1 v8 9.4.146.24-node.14
16.13.0 v8 9.4.146.19-node.13
16.12.0 v8 9.4.146.19-node.13
16.11.1 v8 9.4.146.19-node.13
16.11.0 v8 9.4.146.19-node.13
99% complete99% complete 		16.10.0
(these versions have identical results)
16.10.0 v8 9.3.345.19-node.14
16.9.1 v8 9.3.345.16-node.12
16.9.0 v8 9.3.345.16-node.11
99% complete99% complete 		16.8.0
(these versions have identical results)
16.8.0 v8 9.2.230.21-node.20
16.7.0 v8 9.2.230.21-node.19
16.6.2 v8 9.2.230.21-node.19
16.6.1 v8 9.2.230.21-node.19
16.6.0 v8 9.2.230.21-node.18
99% complete99% complete 		16.5.0
(these versions have identical results)
16.5.0 v8 9.1.269.38-node.20
16.4.2 v8 9.1.269.36-node.14
16.4.1 v8 9.1.269.36-node.14
16.4.0 v8 9.1.269.36-node.14
99% complete99% complete 		16.3.0
(these versions have identical results)
16.3.0 v8 9.0.257.25-node.16
16.2.0 v8 9.0.257.25-node.16
16.1.0 v8 9.0.257.24-node.11
99% complete99% complete 		16.0.0
(these versions have identical results)
16.0.0 v8 9.0.257.17-node.10
99% complete99% complete 		15.14.0
(these versions have identical results)
15.14.0 v8 8.6.395.17-node.28
15.13.0 v8 8.6.395.17-node.28
15.12.0 v8 8.6.395.17-node.27
15.11.0 v8 8.6.395.17-node.27
15.10.0 v8 8.6.395.17-node.25
15.9.0 v8 8.6.395.17-node.25
15.8.0 v8 8.6.395.17-node.23
15.7.0 v8 8.6.395.17-node.23
15.6.0 v8 8.6.395.17-node.23
15.5.1 v8 8.6.395.17-node.23
15.5.0 v8 8.6.395.17-node.23
15.4.0 v8 8.6.395.17-node.22
15.3.0 v8 8.6.395.17-node.22
15.2.1 v8 8.6.395.17-node.17
15.2.0 v8 8.6.395.17-node.17
15.1.0 v8 8.6.395.17-node.16
15.0.1 v8 8.6.395.17-node.15
15.0.0 v8 8.6.395.16-node.15
99% complete99% complete 		14.21.3
(these versions have identical results)
14.21.3 v8 8.4.371.23-node.88
14.21.2 v8 8.4.371.23-node.88
14.21.1 v8 8.4.371.23-node.87
14.21.0 v8 8.4.371.23-node.87
14.20.1 v8 8.4.371.23-node.87
14.20.0 v8 8.4.371.23-node.87
14.19.3 v8 8.4.371.23-node.87
14.19.2 v8 8.4.371.23-node.87
14.19.1 v8 8.4.371.23-node.85
14.19.0 v8 8.4.371.23-node.85
99% complete99% complete 		14.18.3
(these versions have identical results)
14.18.3 v8 8.4.371.23-node.85
14.18.2 v8 8.4.371.23-node.85
14.18.1 v8 8.4.371.23-node.84
14.18.0 v8 8.4.371.23-node.84
14.17.6 v8 8.4.371.23-node.76
14.17.5 v8 8.4.371.23-node.76
14.17.4 v8 8.4.371.23-node.76
14.17.3 v8 8.4.371.23-node.67
14.17.2 v8 8.4.371.23-node.67
14.17.1 v8 8.4.371.23-node.67
14.17.0 v8 8.4.371.23-node.63
14.16.1 v8 8.4.371.19-node.18
14.16.0 v8 8.4.371.19-node.18
14.15.5 v8 8.4.371.19-node.18
14.15.4 v8 8.4.371.19-node.17
14.15.3 v8 8.4.371.19-node.17
14.15.2 v8 8.4.371.19-node.17
14.15.1 v8 8.4.371.19-node.17
14.15.0 v8 8.4.371.19-node.17
14.14.0 v8 8.4.371.19-node.17
14.13.1 v8 8.4.371.19-node.16
14.13.0 v8 8.4.371.19-node.16
14.12.0 v8 8.4.371.19-node.16
14.11.0 v8 8.4.371.19-node.16
14.10.1 v8 8.4.371.19-node.16
14.10.0 v8 8.4.371.19-node.16
14.9.0 v8 8.4.371.19-node.13
14.8.0 v8 8.4.371.19-node.12
14.7.0 v8 8.4.371.19-node.12
14.6.0 v8 8.4.371.19-node.12
99% complete99% complete 		14.5.0
(these versions have identical results)
14.5.0 v8 8.3.110.9-node.23
14.4.0 v8 8.1.307.31-node.33
14.3.0 v8 8.1.307.31-node.33
14.2.0 v8 8.1.307.31-node.33
14.1.0 v8 8.1.307.31-node.32
14.0.0 v8 8.1.307.30-node.30
99% complete99% complete 		13.14.0
(these versions have identical results)
13.14.0 v8 7.9.317.25-node.32
13.13.0 v8 7.9.317.25-node.30
13.12.0 v8 7.9.317.25-node.30
99% complete99% complete 		13.11.0
(these versions have identical results)
13.11.0 v8 7.9.317.25-node.29
13.10.1 v8 7.9.317.25-node.29
13.10.0 v8 7.9.317.25-node.29
13.9.0 v8 7.9.317.25-node.28
13.8.0 v8 7.9.317.25-node.28
13.7.0 v8 7.9.317.25-node.28
13.6.0 v8 7.9.317.25-node.26
13.5.0 v8 7.9.317.25-node.23
13.4.0 v8 7.9.317.25-node.23
13.3.0 v8 7.9.317.25-node.23
13.2.0 v8 7.9.317.23-node.20
99% complete99% complete 		13.1.0
(these versions have identical results)
13.1.0 v8 7.8.279.17-node.19
13.0.1 v8 7.8.279.17-node.14
13.0.0 v8 7.8.279.17-node.14
99% complete99% complete 		12.22.12
(these versions have identical results)
12.22.12 v8 7.8.279.23-node.57
12.22.11 v8 7.8.279.23-node.56
12.22.10 v8 7.8.279.23-node.56
12.22.9 v8 7.8.279.23-node.56
12.22.8 v8 7.8.279.23-node.56
12.22.7 v8 7.8.279.23-node.56
12.22.6 v8 7.8.279.23-node.56
12.22.5 v8 7.8.279.23-node.56
12.22.4 v8 7.8.279.23-node.56
12.22.3 v8 7.8.279.23-node.46
12.22.2 v8 7.8.279.23-node.46
12.22.1 v8 7.8.279.23-node.46
12.22.0 v8 7.8.279.23-node.46
12.21.0 v8 7.8.279.23-node.45
12.20.2 v8 7.8.279.23-node.45
12.20.1 v8 7.8.279.23-node.45
12.20.0 v8 7.8.279.23-node.45
12.19.1 v8 7.8.279.23-node.44
12.19.0 v8 7.8.279.23-node.44
12.18.4 v8 7.8.279.23-node.39
12.18.3 v8 7.8.279.23-node.39
12.18.2 v8 7.8.279.23-node.39
12.18.1 v8 7.8.279.23-node.38
12.18.0 v8 7.8.279.23-node.37
12.17.0 v8 7.8.279.23-node.37
99% complete99% complete 		12.16.3
(these versions have identical results)
12.16.3 v8 7.8.279.23-node.35
12.16.2 v8 7.8.279.23-node.34
12.16.1 v8 7.8.279.23-node.31
12.16.0 v8 7.8.279.23-node.31
12.15.0 v8 7.7.299.13-node.16
12.14.1 v8 7.7.299.13-node.16
12.14.0 v8 7.7.299.13-node.16
12.13.1 v8 7.7.299.13-node.16
12.13.0 v8 7.7.299.13-node.12
12.12.0 v8 7.7.299.13-node.12
12.11.1 v8 7.7.299.11-node.12
12.11.0 v8 7.7.299.11-node.12
99% complete99% complete 		12.10.0
(these versions have identical results)
12.10.0 v8 7.6.303.29-node.16
12.9.1 v8 7.6.303.29-node.15
12.9.0 v8 7.6.303.29-node.15
99% complete99% complete 		12.8.1
(these versions have identical results)
12.8.1 v8 7.5.288.22-node.16
12.8.0 v8 7.5.288.22-node.16
12.7.0 v8 7.5.288.22-node.16
12.6.0 v8 7.5.288.22-node.14
12.5.0 v8 7.5.288.22-node.14
99% complete99% complete 		12.4.0
(these versions have identical results)
12.4.0 v8 7.4.288.27-node.18
12.3.1 v8 7.4.288.27-node.18
12.3.0 v8 7.4.288.27-node.17
12.2.0 v8 7.4.288.21-node.17
12.1.0 v8 7.4.288.21-node.16
99% complete99% complete 		12.0.0
(these versions have identical results)
12.0.0 v8 7.4.288.21-node.16
99% complete99% complete 		11.15.0
(these versions have identical results)
11.15.0 v8 7.0.276.38-node.19
11.14.0 v8 7.0.276.38-node.18
11.13.0 v8 7.0.276.38-node.18
11.12.0 v8 7.0.276.38-node.18
11.11.0 v8 7.0.276.38-node.18
11.10.1 v8 7.0.276.38-node.17
11.10.0 v8 7.0.276.38-node.17
11.9.0 v8 7.0.276.38-node.16
11.8.0 v8 7.0.276.38-node.16
11.7.0 v8 7.0.276.38-node.16
11.6.0 v8 7.0.276.38-node.13
11.5.0 v8 7.0.276.38-node.13
11.4.0 v8 7.0.276.38-node.13
11.3.0 v8 7.0.276.38-node.11
11.2.0 v8 7.0.276.38-node.11
11.1.0 v8 7.0.276.32-node.7
11.0.0 v8 7.0.276.28-node.5
99% complete99% complete 		10.24.1
(these versions have identical results)
10.24.1 v8 6.8.275.32-node.59
10.24.0 v8 6.8.275.32-node.59
10.23.3 v8 6.8.275.32-node.59
10.23.2 v8 6.8.275.32-node.59
10.23.1 v8 6.8.275.32-node.59
10.23.0 v8 6.8.275.32-node.59
10.22.1 v8 6.8.275.32-node.58
10.22.0 v8 6.8.275.32-node.58
10.21.0 v8 6.8.275.32-node.56
10.20.1 v8 6.8.275.32-node.56
10.20.0 v8 6.8.275.32-node.56
10.19.0 v8 6.8.275.32-node.55
10.18.1 v8 6.8.275.32-node.55
10.18.0 v8 6.8.275.32-node.54
10.17.0 v8 6.8.275.32-node.54
10.16.3 v8 6.8.275.32-node.54
10.16.2 v8 6.8.275.32-node.54
10.16.1 v8 6.8.275.32-node.54
10.16.0 v8 6.8.275.32-node.52
99% complete99% complete 		10.15.3
(these versions have identical results)
10.15.3 v8 6.8.275.32-node.51
10.15.2 v8 6.8.275.32-node.12
10.15.1 v8 6.8.275.32-node.12
10.15.0 v8 6.8.275.32-node.45
10.14.2 v8 6.8.275.32-node.45
10.14.1 v8 6.8.275.32-node.36
10.14.0 v8 6.8.275.32-node.36
10.13.0 v8 6.8.275.32-node.36
10.12.0 v8 6.8.275.32-node.35
10.11.0 v8 6.8.275.32-node.28
10.10.0 v8 6.8.275.30-node.24
10.9.0 v8 6.8.275.24-node.14
99% complete99% complete 		10.8.0
(these versions have identical results)
10.8.0 v8 6.7.288.49-node.19
10.7.0 v8 6.7.288.49-node.15
10.6.0 v8 6.7.288.46-node.13
99% complete99% complete 		10.5.0
(these versions have identical results)
10.5.0 v8 6.7.288.46-node.8
10.4.1 v8 6.7.288.45-node.7
10.4.0 v8 6.7.288.43-node.7
99% complete99% complete 		10.3.0
(these versions have identical results)
10.3.0 v8 6.6.346.32-node.9
10.2.1 v8 6.6.346.32-node.8
10.2.0 v8 6.6.346.32-node.8
10.1.0 v8 6.6.346.27-node.6
10.0.0 v8 6.6.346.24-node.5
99% complete99% complete 		9.11.2
(these versions have identical results)
9.11.2 v8 6.2.414.46-node.23
9.11.1 v8 6.2.414.46-node.23
9.11.0 v8 6.2.414.46-node.23
9.10.1 v8 6.2.414.46-node.23
9.10.0 v8 6.2.414.46-node.23
9.9.0 v8 6.2.414.46-node.22
9.8.0 v8 6.2.414.46-node.21
9.7.1 v8 6.2.414.46-node.20
9.7.0 v8 6.2.414.46-node.20
9.6.1 v8 6.2.414.46-node.20
9.6.0 v8 6.2.414.46-node.20
9.5.0 v8 6.2.414.46-node.18
9.4.0 v8 6.2.414.46-node.17
9.3.0 v8 6.2.414.46-node.15
9.2.1 v8 6.2.414.44-node.11
9.2.0 v8 6.2.414.44-node.11
9.1.0 v8 6.2.414.32-node.8
9.0.0 v8 6.2.414.32-node.8
8.17.0 v8 6.2.414.78
8.16.2 v8 6.2.414.78
8.16.1 v8 6.2.414.77
8.16.0 v8 6.2.414.77
8.15.1 v8 6.2.414.75
8.15.0 v8 6.2.414.75
8.14.1 v8 6.2.414.75
8.14.0 v8 6.2.414.72
8.13.0 v8 6.2.414.72
8.12.0 v8 6.2.414.66
8.11.4 v8 6.2.414.54
8.11.3 v8 6.2.414.54
8.11.2 v8 6.2.414.54
8.11.1 v8 6.2.414.50
8.11.0 v8 6.2.414.50
8.10.0 v8 6.2.414.50
99% complete99% complete 		8.9.4
(these versions have identical results)
8.9.4 v8 6.1.534.50
8.9.3 v8 6.1.534.48
8.9.2 v8 6.1.534.48
8.9.1 v8 6.1.534.47
8.9.0 v8 6.1.534.46
8.8.1 v8 6.1.534.42
8.8.0 v8 6.1.534.42
8.7.0 v8 6.1.534.42
99% complete99% complete 		8.6.0
(these versions have identical results)
8.6.0 v8 6.0.287.53
8.5.0 v8 6.0.287.53
8.4.0 v8 6.0.286.52
8.3.0 v8 6.0.286.52
99% complete99% complete 		8.2.1
(these versions have identical results)
8.2.1 v8 5.8.283.41
8.2.0 v8 5.8.283.41
8.1.4 v8 5.8.283.41
8.1.3 v8 5.8.283.41
8.1.2 v8 5.8.283.41
8.1.1 v8 5.8.283.41
8.1.0 v8 5.8.283.41
8.0.0 v8 5.8.283.41
99% complete99% complete 		7.10.1
(these versions have identical results)
7.10.1 v8 5.5.372.43
7.10.0 v8 5.5.372.43
7.9.0 v8 5.5.372.43
7.8.0 v8 5.5.372.43
7.7.4 v8 5.5.372.42
7.7.3 v8 5.5.372.41
7.7.2 v8 5.5.372.41
7.7.1 v8 5.5.372.41
7.7.0 v8 5.5.372.41
7.6.0 v8 5.5.372.40
99% complete98% complete 		7.5.0
(these versions have identical results)
7.5.0 v8 5.4.500.48
7.4.0 v8 5.4.500.45
7.3.0 v8 5.4.500.45
7.2.1 v8 5.4.500.44
7.2.0 v8 5.4.500.43
7.1.0 v8 5.4.500.36
7.0.0 v8 5.4.500.36
99% complete98% complete 		6.17.1
(these versions have identical results)
6.17.1 v8 5.1.281.111
6.17.0 v8 5.1.281.111
6.16.0 v8 5.1.281.111
6.15.1 v8 5.1.281.111
6.15.0 v8 5.1.281.111
6.14.4 v8 5.1.281.111
6.14.3 v8 5.1.281.111
6.14.2 v8 5.1.281.111
6.14.1 v8 5.1.281.111
6.14.0 v8 5.1.281.111
6.13.1 v8 5.1.281.111
6.13.0 v8 5.1.281.111
6.12.3 v8 5.1.281.111
6.12.2 v8 5.1.281.109
6.12.1 v8 5.1.281.109
6.12.0 v8 5.1.281.108
6.11.5 v8 5.1.281.108
6.11.4 v8 5.1.281.108
6.11.3 v8 5.1.281.107
6.11.2 v8 5.1.281.103
6.11.1 v8 5.1.281.103
6.11.0 v8 5.1.281.102
6.10.3 v8 5.1.281.101
6.10.2 v8 5.1.281.98
6.10.1 v8 5.1.281.95
6.10.0 v8 5.1.281.93
6.9.5 v8 5.1.281.89
6.9.4 v8 5.1.281.89
6.9.3 v8 5.1.281.89
6.9.2 v8 5.1.281.88
6.9.1 v8 5.1.281.84
6.9.0 v8 5.1.281.84
6.8.1 v8 5.1.281.84
6.8.0 v8 5.1.281.84
6.7.0 v8 5.1.281.83
6.6.0 v8 5.1.281.83
6.5.0 v8 5.1.281.81
99% complete98% complete 		6.4.0
(these versions have identical results)
6.4.0 v8 5.0.71.60
6.3.1 v8 5.0.71.57
6.3.0 v8 5.0.71.52
6.2.2 v8 5.0.71.52
6.2.1 v8 5.0.71.52
6.2.0 v8 5.0.71.47
6.1.0 v8 5.0.71.35
6.0.0 v8 5.0.71.35
95% complete91% complete 		5.12.0
(these versions have identical results)
5.12.0 v8 4.6.85.32
5.11.1 v8 4.6.85.31
5.11.0 v8 4.6.85.31
5.10.1 v8 4.6.85.31
5.10.0 v8 4.6.85.31
5.9.1 v8 4.6.85.31
5.9.0 v8 4.6.85.31
5.8.0 v8 4.6.85.31
5.7.1 v8 4.6.85.31
5.7.0 v8 4.6.85.31
5.6.0 v8 4.6.85.31
5.5.0 v8 4.6.85.31
5.4.1 v8 4.6.85.31
5.4.0 v8 4.6.85.31
5.3.0 v8 4.6.85.31
5.2.0 v8 4.6.85.31
5.1.1 v8 4.6.85.31
5.1.0 v8 4.6.85.31
5.0.0 v8 4.6.85.28
57% complete46% complete 		4.9.1
(these versions have identical results)
4.9.1 v8 4.5.103.53
4.9.0 v8 4.5.103.53
4.8.7 v8 4.5.103.53
4.8.6 v8 4.5.103.53
4.8.5 v8 4.5.103.47
4.8.4 v8 4.5.103.47
4.8.3 v8 4.5.103.47
4.8.2 v8 4.5.103.46
4.8.1 v8 4.5.103.46
4.8.0 v8 4.5.103.45
4.7.3 v8 4.5.103.43
4.7.2 v8 4.5.103.43
4.7.1 v8 4.5.103.43
4.7.0 v8 4.5.103.43
4.6.2 v8 4.5.103.42
4.6.1 v8 4.5.103.37
4.6.0 v8 4.5.103.37
4.5.0 v8 4.5.103.37
4.4.7 v8 4.5.103.36
4.4.6 v8 4.5.103.36
4.4.5 v8 4.5.103.35
4.4.4 v8 4.5.103.35
4.4.3 v8 4.5.103.35
4.4.2 v8 4.5.103.35
4.4.1 v8 4.5.103.35
4.4.0 v8 4.5.103.35
4.3.2 v8 4.5.103.35
4.3.1 v8 4.5.103.35
4.3.0 v8 4.5.103.35
4.2.6 v8 4.5.103.35
4.2.5 v8 4.5.103.35
4.2.4 v8 4.5.103.35
4.2.3 v8 4.5.103.35
4.2.2 v8 4.5.103.35
4.2.1 v8 4.5.103.35
4.2.0 v8 4.5.103.35
4.1.2 v8 4.5.103.35
4.1.1 v8 4.5.103.33
4.1.0 v8 4.5.103.33
4.0.0 v8 4.5.103.30
47% complete43% complete 		0.12.18
(these versions have identical results)
0.12.18 v8 3.28.71.20
29% complete22% complete 		0.10.48
(these versions have identical results)
0.10.48 v8 3.14.5.11
10% complete6% complete

optimisation

proper tail calls (tail call optimisation)

§direct recursion
?
function(){
"use strict"; return (function f(n){ if (n <= 0) { return "foo"; } return f(n - 1); }(1e6)) === "foo";
}
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function(){
"use strict"; return (function f(n){ if (n <= 0) { return "foo"; } return f(n - 1); }(1e6)) === "foo";
}
§mutual recursion
?
function(){
"use strict"; function f(n){ if (n <= 0) { return "foo"; } return g(n - 1); } function g(n){ if (n <= 0) { return "bar"; } return f(n - 1); } return f(1e6) === "foo" && f(1e6+1) === "bar";
}
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function(){
"use strict"; function f(n){ if (n <= 0) { return "foo"; } return g(n - 1); } function g(n){ if (n <= 0) { return "bar"; } return f(n - 1); } return f(1e6) === "foo" && f(1e6+1) === "bar";
}

syntax

default function parameters

§basic functionality
?
function(){
return (function (a = 1, b = 2) { return a === 3 && b === 2; }(3));
}
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function(){
return (function (a = 1, b = 2) { return a === 3 && b === 2; }(3));
}
§explicit undefined defers to the default
?
function(){
return (function (a = 1, b = 2) { return a === 1 && b === 3; }(undefined, 3));
}
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function(){
return (function (a = 1, b = 2) { return a === 1 && b === 3; }(undefined, 3));
}
§defaults can refer to previous params
?
function(){
return (function (a, b = a) { return b === 5; }(5));
}
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function(){
return (function (a, b = a) { return b === 5; }(5));
}
§arguments object interaction
?
function(){
return (function (a = "baz", b = "qux", c = "quux") { a = "corge"; // The arguments object is not mapped to the // parameters, even outside of strict mode. return arguments.length === 2 && arguments[0] === "foo" && arguments[1] === "bar"; }("foo", "bar"));
}
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function(){
return (function (a = "baz", b = "qux", c = "quux") { a = "corge"; // The arguments object is not mapped to the // parameters, even outside of strict mode. return arguments.length === 2 && arguments[0] === "foo" && arguments[1] === "bar"; }("foo", "bar"));
}
§temporal dead zone
?
function(){
return (function(x = 1) { try { eval("(function(a=a){}())"); return false; } catch(e) {} try { eval("(function(a=b,b){}())"); return false; } catch(e) {} return true; }());
}
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function(){
return (function(x = 1) { try { eval("(function(a=a){}())"); return false; } catch(e) {} try { eval("(function(a=b,b){}())"); return false; } catch(e) {} return true; }());
}
§separate scope
?
function(){
return (function(a=function(){ return typeof b === 'undefined'; }){ var b = 1; return a(); }());
}
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function(){
return (function(a=function(){ return typeof b === 'undefined'; }){ var b = 1; return a(); }());
}
§new Function() support
?
function(){
return new Function("a = 1", "b = 2", "return a === 3 && b === 2;" )(3);
}
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function(){
return new Function("a = 1", "b = 2", "return a === 3 && b === 2;" )(3);
}

rest parameters

§basic functionality
?
function(){
return (function (foo, ...args) { return args instanceof Array && args + "" === "bar,baz"; }("foo", "bar", "baz"));
}
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function(){
return (function (foo, ...args) { return args instanceof Array && args + "" === "bar,baz"; }("foo", "bar", "baz"));
}
§function 'length' property
?
function(){
return function(a, ...b){}.length === 1 && function(...c){}.length === 0;
}
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Error
Flag
Error
Flag
Error
Error
Error
Error
function(){
return function(a, ...b){}.length === 1 && function(...c){}.length === 0;
}
§arguments object interaction
?
function(){
return (function (foo, ...args) { foo = "qux"; // The arguments object is not mapped to the // parameters, even outside of strict mode. return arguments.length === 3 && arguments[0] === "foo" && arguments[1] === "bar" && arguments[2] === "baz"; }("foo", "bar", "baz"));
}
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Error
Flag
Error
Flag
Error
Error
Error
Error
function(){
return (function (foo, ...args) { foo = "qux"; // The arguments object is not mapped to the // parameters, even outside of strict mode. return arguments.length === 3 && arguments[0] === "foo" && arguments[1] === "bar" && arguments[2] === "baz"; }("foo", "bar", "baz"));
}
§can't be used in setters
?
function(){
return (function (...args) { try { eval("({set e(...args){}})"); } catch(e) { return true; } }());
}
Yes
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Error
Flag
Error
Flag
Error
Error
Error
Error
function(){
return (function (...args) { try { eval("({set e(...args){}})"); } catch(e) { return true; } }());
}
§new Function() support
?
function(){
return new Function("a", "...b", "return b instanceof Array && a+b === 'foobar,baz';" )('foo','bar','baz');
}
Yes
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Error
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Error
Flag
Error
Error
Error
Error
function(){
return new Function("a", "...b", "return b instanceof Array && a+b === 'foobar,baz';" )('foo','bar','baz');
}

spread syntax for iterable objects

§with arrays, in function calls
?
function(){
return Math.max(...[1, 2, 3]) === 3
}
Yes
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Error
Flag
Error
Error
Error
Error
function(){
return Math.max(...[1, 2, 3]) === 3
}
§with arrays, in array literals
?
function(){
return [...[1, 2, 3]][2] === 3;
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
return [...[1, 2, 3]][2] === 3;
}
§with sparse arrays, in function calls
?
function(){
var a = Array(...[,,]); return "0" in a && "1" in a && '' + a[0] + a[1] === "undefinedundefined";
}
Yes
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Error
Flag
Error
Error
Error
Error
function(){
var a = Array(...[,,]); return "0" in a && "1" in a && '' + a[0] + a[1] === "undefinedundefined";
}
§with sparse arrays, in array literals
?
function(){
var a = [...[,,]]; return "0" in a && "1" in a && '' + a[0] + a[1] === "undefinedundefined";
}
Yes
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Error
Flag
Error
Error
Error
Error
function(){
var a = [...[,,]]; return "0" in a && "1" in a && '' + a[0] + a[1] === "undefinedundefined";
}
§with strings, in function calls
?
function(){
return Math.max(..."1234") === 4;
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
return Math.max(..."1234") === 4;
}
§with strings, in array literals
?
function(){
return ["a", ..."bcd", "e"][3] === "d";
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
return ["a", ..."bcd", "e"][3] === "d";
}
§with astral plane strings, in function calls
?
function(){
return Array(..."𠮷𠮶")[0] === "𠮷";
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
return Array(..."𠮷𠮶")[0] === "𠮷";
}
§with astral plane strings, in array literals
?
function(){
return [..."𠮷𠮶"][0] === "𠮷";
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
return [..."𠮷𠮶"][0] === "𠮷";
}
§with generator instances, in calls
?
function(){
var iterable = (function*(){ yield 1; yield 2; yield 3; }()); return Math.max(...iterable) === 3;
}
Yes
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Error
Flag
Error
Error
Error
Error
function(){
var iterable = (function*(){ yield 1; yield 2; yield 3; }()); return Math.max(...iterable) === 3;
}
§with generator instances, in arrays
?
function(){
var iterable = (function*(){ yield "b"; yield "c"; yield "d"; }()); return ["a", ...iterable, "e"][3] === "d";
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
var iterable = (function*(){ yield "b"; yield "c"; yield "d"; }()); return ["a", ...iterable, "e"][3] === "d";
}
§with generic iterables, in calls
?
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Math.max(...iterable) === 3;
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Math.max(...iterable) === 3;
}
§with generic iterables, in arrays
?
function(){
var iterable = global.__createIterableObject(["b", "c", "d"]); return ["a", ...iterable, "e"][3] === "d";
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
var iterable = global.__createIterableObject(["b", "c", "d"]); return ["a", ...iterable, "e"][3] === "d";
}
§with instances of iterables, in calls
?
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Math.max(...Object.create(iterable)) === 3;
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Math.max(...Object.create(iterable)) === 3;
}
§with instances of iterables, in arrays
?
function(){
var iterable = global.__createIterableObject(["b", "c", "d"]); return ["a", ...Object.create(iterable), "e"][3] === "d";
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
var iterable = global.__createIterableObject(["b", "c", "d"]); return ["a", ...Object.create(iterable), "e"][3] === "d";
}
§spreading non-iterables is a runtime error
?
function(){
try { Math.max(...2); } catch(e) { return Math.max(...[1, 2, 3]) === 3; }
}
Yes
Yes
Yes
Yes
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Error
Flag
Error
Error
Error
Error
function(){
try { Math.max(...2); } catch(e) { return Math.max(...[1, 2, 3]) === 3; }
}

object literal extensions

§computed properties
?
function(){
var x = 'y'; return ({ [x]: 1 }).y === 1;
}
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var x = 'y'; return ({ [x]: 1 }).y === 1;
}
§shorthand properties
?
function(){
var a = 7, b = 8, c = {a,b}; return c.a === 7 && c.b === 8;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var a = 7, b = 8, c = {a,b}; return c.a === 7 && c.b === 8;
}
§shorthand methods
?
function(){
return ({ y() { return 2; } }).y() === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
return ({ y() { return 2; } }).y() === 2;
}
§string-keyed shorthand methods
?
function(){
return ({ "foo bar"() { return 4; } })["foo bar"]() === 4;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
return ({ "foo bar"() { return 4; } })["foo bar"]() === 4;
}
§computed shorthand methods
?
function(){
var x = 'y'; return ({ [x](){ return 1 } }).y() === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var x = 'y'; return ({ [x](){ return 1 } }).y() === 1;
}
§computed accessors
?
function(){
var x = 'y', valueSet, obj = { get [x] () { return 1 }, set [x] (value) { valueSet = value } }; obj.y = 'foo'; return obj.y === 1 && valueSet === 'foo';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var x = 'y', valueSet, obj = { get [x] () { return 1 }, set [x] (value) { valueSet = value } }; obj.y = 'foo'; return obj.y === 1 && valueSet === 'foo';
}

for..of loops

§with arrays
?
function(){
var arr = [5]; for (var item of arr) return item === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var arr = [5]; for (var item of arr) return item === 5;
}
§with sparse arrays
?
function(){
var arr = [,,]; var count = 0; for (var item of arr) count += (item === void undefined); return count === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var arr = [,,]; var count = 0; for (var item of arr) count += (item === void undefined); return count === 2;
}
§with strings
?
function(){
var str = ""; for (var item of "foo") str += item; return str === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var str = ""; for (var item of "foo") str += item; return str === "foo";
}
§with astral plane strings
?
function(){
var str = ""; for (var item of "𠮷𠮶") str += item + " "; return str === "𠮷 𠮶 ";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var str = ""; for (var item of "𠮷𠮶") str += item + " "; return str === "𠮷 𠮶 ";
}
§with generator instances
?
function(){
var result = ""; var iterable = (function*(){ yield 1; yield 2; yield 3; }()); for (var item of iterable) { result += item; } return result === "123";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var result = ""; var iterable = (function*(){ yield 1; yield 2; yield 3; }()); for (var item of iterable) { result += item; } return result === "123";
}
§with generic iterables
?
function(){
var result = ""; var iterable = global.__createIterableObject([1, 2, 3]); for (var item of iterable) { result += item; } return result === "123";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var result = ""; var iterable = global.__createIterableObject([1, 2, 3]); for (var item of iterable) { result += item; } return result === "123";
}
§with instances of generic iterables
?
function(){
var result = ""; var iterable = global.__createIterableObject([1, 2, 3]); for (var item of Object.create(iterable)) { result += item; } return result === "123";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var result = ""; var iterable = global.__createIterableObject([1, 2, 3]); for (var item of Object.create(iterable)) { result += item; } return result === "123";
}
§iterator closing, break
?
function(){
var closed = false; var iter = __createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); for (var it of iter) break; return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
Error
Error
function(){
var closed = false; var iter = __createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); for (var it of iter) break; return closed;
}
§iterator closing, throw
?
function(){
var closed = false; var iter = __createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { for (var it of iter) throw 0; } catch(e){} return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
Error
Error
function(){
var closed = false; var iter = __createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { for (var it of iter) throw 0; } catch(e){} return closed;
}

octal and binary literals

§octal literals
?
function(){
return 0o10 === 8 && 0O10 === 8;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
return 0o10 === 8 && 0O10 === 8;
}
§binary literals
?
function(){
return 0b10 === 2 && 0B10 === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
return 0b10 === 2 && 0B10 === 2;
}
§octal supported by Number()
?
function(){
return Number('0o1') === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
function(){
return Number('0o1') === 1;
}
§binary supported by Number()
?
function(){
return Number('0b1') === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
function(){
return Number('0b1') === 1;
}

template literals

§basic functionality
?
function(){
var a = "ba", b = "QUX"; return `foo bar ${a + "z"} ${b.toLowerCase()}` === "foo bar\nbaz qux";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Error
Error
Error
Error
function(){
var a = "ba", b = "QUX"; return `foo bar ${a + "z"} ${b.toLowerCase()}` === "foo bar\nbaz qux";
}
§toString conversion
?
function(){
var a = { toString: function() { return "foo"; }, valueOf: function() { return "bar"; } }; return `${a}` === "foo";
}
Yes
Yes
Yes
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Yes
Error
Error
Error
Error
function(){
var a = { toString: function() { return "foo"; }, valueOf: function() { return "bar"; } }; return `${a}` === "foo";
}
§tagged template literals
?
function(){
var called = false; function fn(parts, a, b) { called = true; return parts instanceof Array && parts[0] === "foo" && parts[1] === "bar\n" && parts.raw[0] === "foo" && parts.raw[1] === "bar\\n" && a === 123 && b === 456; } return fn `foo${123}bar\n${456}` && called;
}
Yes
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Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var called = false; function fn(parts, a, b) { called = true; return parts instanceof Array && parts[0] === "foo" && parts[1] === "bar\n" && parts.raw[0] === "foo" && parts.raw[1] === "bar\\n" && a === 123 && b === 456; } return fn `foo${123}bar\n${456}` && called;
}
§passed array is frozen
?
function(){
return (function(parts) { return Object.isFrozen(parts) && Object.isFrozen(parts.raw); }) `foo${0}bar${0}baz`;
}
Yes
Yes
Yes
Yes
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Yes
Error
Error
Error
Error
function(){
return (function(parts) { return Object.isFrozen(parts) && Object.isFrozen(parts.raw); }) `foo${0}bar${0}baz`;
}
§line break normalisation
?
function(){
var cr = eval("`x" + String.fromCharCode(13) + "y`"); var lf = eval("`x" + String.fromCharCode(10) + "y`"); var crlf = eval("`x" + String.fromCharCode(13,10) + "y`"); return cr.length === 3 && lf.length === 3 && crlf.length === 3 && cr[1] === lf[1] && lf[1] === crlf[1] && crlf[1] === '\n';
}
Yes
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Yes
Error
Error
Error
Error
function(){
var cr = eval("`x" + String.fromCharCode(13) + "y`"); var lf = eval("`x" + String.fromCharCode(10) + "y`"); var crlf = eval("`x" + String.fromCharCode(13,10) + "y`"); return cr.length === 3 && lf.length === 3 && crlf.length === 3 && cr[1] === lf[1] && lf[1] === crlf[1] && crlf[1] === '\n';
}
§TemplateStrings call site caching
?
function(){
// TemplateStrings caching was changed from per-contents to // per-call-site. // https://github.com/tc39/ecma262/pull/890 function strings(array) { return array; } function getStrings() { return strings`foo`; } var original = getStrings(); var other = strings`foo`; return original === getStrings() && original !== other;
}
Yes
Yes
Yes
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No
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No
No
No
No
Error
Error
Error
Error
function(){
// TemplateStrings caching was changed from per-contents to // per-call-site. // https://github.com/tc39/ecma262/pull/890 function strings(array) { return array; } function getStrings() { return strings`foo`; } var original = getStrings(); var other = strings`foo`; return original === getStrings() && original !== other;
}
§TemplateStrings permanent caching
?
function(){
function strings(array) { return array; } function getStrings() { return strings`foo`; } var original = getStrings(); var newed = new getStrings(); return original === getStrings() && original === newed;
}
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
function strings(array) { return array; } function getStrings() { return strings`foo`; } var original = getStrings(); var newed = new getStrings(); return original === getStrings() && original === newed;
}

RegExp "y" and "u" flags

§"y" flag
?
function(){
var re = new RegExp('\\w', 'y'); re.exec('xy'); return (re.exec('xy')[0] === 'y');
}
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var re = new RegExp('\\w', 'y'); re.exec('xy'); return (re.exec('xy')[0] === 'y');
}
§"y" flag, lastIndex
?
function(){
var re = new RegExp('yy', 'y'); re.lastIndex = 3; var result = re.exec('xxxyyxx')[0]; return result === 'yy' && re.lastIndex === 5;
}
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var re = new RegExp('yy', 'y'); re.lastIndex = 3; var result = re.exec('xxxyyxx')[0]; return result === 'yy' && re.lastIndex === 5;
}
§"u" flag
?
function(){
return "𠮷".match(/^.$/u)[0].length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return "𠮷".match(/^.$/u)[0].length === 2;
}
§"u" flag, non-BMP Unicode characters
?
function(){
return "𠮷x".match(/^.x$/u)[0].length === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return "𠮷x".match(/^.x$/u)[0].length === 3;
}
§"u" flag, Unicode code point escapes
?
function(){
return "𝌆".match(/\u{1d306}/u)[0].length === 2;
}
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return "𝌆".match(/\u{1d306}/u)[0].length === 2;
}
§"u" flag, case folding
?
function(){
return "ſ".match(/S/iu) && "S".match(/ſ/iu);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return "ſ".match(/S/iu) && "S".match(/ſ/iu);
}

destructuring, declarations

§with arrays
?
function(){
var [a, , [b], c] = [5, null, [6]]; return a === 5 && b === 6 && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [a, , [b], c] = [5, null, [6]]; return a === 5 && b === 6 && c === void undefined;
}
§with sparse arrays
?
function(){
var [a, , b] = [,,,]; return a === void undefined && b === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [a, , b] = [,,,]; return a === void undefined && b === void undefined;
}
§with strings
?
function(){
var [a, b, c] = "ab"; return a === "a" && b === "b" && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [a, b, c] = "ab"; return a === "a" && b === "b" && c === void undefined;
}
§with astral plane strings
?
function(){
var [c] = "𠮷𠮶"; return c === "𠮷";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [c] = "𠮷𠮶"; return c === "𠮷";
}
§with generator instances
?
function(){
var [a, b, c] = (function*(){ yield 1; yield 2; }()); return a === 1 && b === 2 && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [a, b, c] = (function*(){ yield 1; yield 2; }()); return a === 1 && b === 2 && c === void undefined;
}
§with generic iterables
?
function(){
var [a, b, c] = global.__createIterableObject([1, 2]); return a === 1 && b === 2 && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [a, b, c] = global.__createIterableObject([1, 2]); return a === 1 && b === 2 && c === void undefined;
}
§with instances of generic iterables
?
function(){
var [a, b, c] = Object.create(global.__createIterableObject([1, 2])); return a === 1 && b === 2 && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [a, b, c] = Object.create(global.__createIterableObject([1, 2])); return a === 1 && b === 2 && c === void undefined;
}
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); var [a, b] = iter; return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); var [a, b] = iter; return closed;
}
§trailing commas in iterable patterns
?
function(){
var [a,] = [1]; return a === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [a,] = [1]; return a === 1;
}
§with objects
?
function(){
var {c, x:d, e} = {c:7, x:8}; return c === 7 && d === 8 && e === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var {c, x:d, e} = {c:7, x:8}; return c === 7 && d === 8 && e === void undefined;
}
§object destructuring with primitives
?
function(){
var {toFixed} = 2; var {slice} = ''; return toFixed === Number.prototype.toFixed && slice === String.prototype.slice;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var {toFixed} = 2; var {slice} = ''; return toFixed === Number.prototype.toFixed && slice === String.prototype.slice;
}
§trailing commas in object patterns
?
function(){
var {a,} = {a:1}; return a === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var {a,} = {a:1}; return a === 1;
}
§throws on null and undefined
?
function(){
try { var {a} = null; return false; } catch(e) { if (!(e instanceof TypeError)) return false; } try { var {b} = void undefined; return false; } catch(e) { if (!(e instanceof TypeError)) return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
try { var {a} = null; return false; } catch(e) { if (!(e instanceof TypeError)) return false; } try { var {b} = void undefined; return false; } catch(e) { if (!(e instanceof TypeError)) return false; } return true;
}
§computed properties
?
function(){
var qux = "corge"; var { [qux]: grault } = { corge: "garply" }; return grault === "garply";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var qux = "corge"; var { [qux]: grault } = { corge: "garply" }; return grault === "garply";
}
§multiples in a single var statement
?
function(){
var [a,b] = [5,6], {c,d} = {c:7,d:8}; return a === 5 && b === 6 && c === 7 && d === 8;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [a,b] = [5,6], {c,d} = {c:7,d:8}; return a === 5 && b === 6 && c === 7 && d === 8;
}
§nested
?
function(){
var [e, {x:f, g}] = [9, {x:10}]; var {h, x:[i]} = {h:11, x:[12]}; return e === 9 && f === 10 && g === void undefined && h === 11 && i === 12;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [e, {x:f, g}] = [9, {x:10}]; var {h, x:[i]} = {h:11, x:[12]}; return e === 9 && f === 10 && g === void undefined && h === 11 && i === 12;
}
§in for-in loop heads
?
function(){
for(var [i, j, k] in { qux: 1 }) { return i === "q" && j === "u" && k === "x"; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
for(var [i, j, k] in { qux: 1 }) { return i === "q" && j === "u" && k === "x"; }
}
§in for-of loop heads
?
function(){
for(var [i, j, k] of [[1,2,3]]) { return i === 1 && j === 2 && k === 3; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
for(var [i, j, k] of [[1,2,3]]) { return i === 1 && j === 2 && k === 3; }
}
§in catch heads
?
function(){
try { throw [1,2]; } catch([i,j]) { try { throw { k: 3, l: 4 }; } catch({k, l}) { return i === 1 && j === 2 && k === 3 && l === 4; } }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
try { throw [1,2]; } catch([i,j]) { try { throw { k: 3, l: 4 }; } catch({k, l}) { return i === 1 && j === 2 && k === 3 && l === 4; } }
}
§rest
?
function(){
var [a, ...b] = [3, 4, 5]; var [c, ...d] = [6]; return a === 3 && b instanceof Array && (b + "") === "4,5" && c === 6 && d instanceof Array && d.length === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var [a, ...b] = [3, 4, 5]; var [c, ...d] = [6]; return a === 3 && b instanceof Array && (b + "") === "4,5" && c === 6 && d instanceof Array && d.length === 0;
}
§defaults
?
function(){
var {a = 1, b = 0, z:c = 3} = {b:2, z:undefined}; var [d = 0, e = 5, f = 6] = [4,,undefined]; return a === 1 && b === 2 && c === 3 && d === 4 && e === 5 && f === 6;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var {a = 1, b = 0, z:c = 3} = {b:2, z:undefined}; var [d = 0, e = 5, f = 6] = [4,,undefined]; return a === 1 && b === 2 && c === 3 && d === 4 && e === 5 && f === 6;
}
§defaults, let temporal dead zone
?
function(){
var {a, b = 2} = {a:1}; try { eval("let {c = c} = {};"); return false; } catch(e){} try { eval("let {c = d, d} = {d:1};"); return false; } catch(e){} return a === 1 && b === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var {a, b = 2} = {a:1}; try { eval("let {c = c} = {};"); return false; } catch(e){} try { eval("let {c = d, d} = {d:1};"); return false; } catch(e){} return a === 1 && b === 2;
}

destructuring, assignment

§with arrays
?
function(){
var a,b,c; [a, , [b], c] = [5, null, [6]]; return a === 5 && b === 6 && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b,c; [a, , [b], c] = [5, null, [6]]; return a === 5 && b === 6 && c === void undefined;
}
§with sparse arrays
?
function(){
var a, b; [a, , b] = [,,,]; return a === void undefined && b === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a, b; [a, , b] = [,,,]; return a === void undefined && b === void undefined;
}
§with strings
?
function(){
var a,b,c; [a, b, c] = "ab"; return a === "a" && b === "b" && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b,c; [a, b, c] = "ab"; return a === "a" && b === "b" && c === void undefined;
}
§with astral plane strings
?
function(){
var c; [c] = "𠮷𠮶"; return c === "𠮷";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var c; [c] = "𠮷𠮶"; return c === "𠮷";
}
§with generator instances
?
function(){
var a,b,c; [a, b, c] = (function*(){ yield 1; yield 2; }()); return a === 1 && b === 2 && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b,c; [a, b, c] = (function*(){ yield 1; yield 2; }()); return a === 1 && b === 2 && c === void undefined;
}
§with generic iterables
?
function(){
var a,b,c; [a, b, c] = global.__createIterableObject([1, 2]); return a === 1 && b === 2 && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b,c; [a, b, c] = global.__createIterableObject([1, 2]); return a === 1 && b === 2 && c === void undefined;
}
§with instances of generic iterables
?
function(){
var a,b,c; [a, b, c] = Object.create(global.__createIterableObject([1, 2])); return a === 1 && b === 2 && c === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b,c; [a, b, c] = Object.create(global.__createIterableObject([1, 2])); return a === 1 && b === 2 && c === void undefined;
}
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); var a,b; [a, b] = iter; return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); var a,b; [a, b] = iter; return closed;
}
§iterable destructuring expression
?
function(){
var a, b, iterable = [1,2]; return ([a, b] = iterable) === iterable;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a, b, iterable = [1,2]; return ([a, b] = iterable) === iterable;
}
§chained iterable destructuring
?
function(){
var a,b,c,d; [a,b] = [c,d] = [1,2]; return a === 1 && b === 2 && c === 1 && d === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b,c,d; [a,b] = [c,d] = [1,2]; return a === 1 && b === 2 && c === 1 && d === 2;
}
§trailing commas in iterable patterns
?
function(){
var a; [a,] = [1]; return a === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a; [a,] = [1]; return a === 1;
}
§with objects
?
function(){
var c,d,e; ({c, x:d, e} = {c:7, x:8}); return c === 7 && d === 8 && e === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var c,d,e; ({c, x:d, e} = {c:7, x:8}); return c === 7 && d === 8 && e === void undefined;
}
§object destructuring with primitives
?
function(){
var toFixed, slice; ({toFixed} = 2); ({slice} = ''); return toFixed === Number.prototype.toFixed && slice === String.prototype.slice;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var toFixed, slice; ({toFixed} = 2); ({slice} = ''); return toFixed === Number.prototype.toFixed && slice === String.prototype.slice;
}
§trailing commas in object patterns
?
function(){
var a; ({a,} = {a:1}); return a === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a; ({a,} = {a:1}); return a === 1;
}
§object destructuring expression
?
function(){
var a, b, obj = { a:1, b:2 }; return ({a,b} = obj) === obj;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a, b, obj = { a:1, b:2 }; return ({a,b} = obj) === obj;
}
§parenthesised left-hand-side is a syntax error
?
function(){
var a, b; ({a,b} = {a:1,b:2}); try { eval("({a,b}) = {a:3,b:4};"); } catch(e) { return a === 1 && b === 2; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a, b; ({a,b} = {a:1,b:2}); try { eval("({a,b}) = {a:3,b:4};"); } catch(e) { return a === 1 && b === 2; }
}
§chained object destructuring
?
function(){
var a,b,c,d; ({a,b} = {c,d} = {a:1,b:2,c:3,d:4}); return a === 1 && b === 2 && c === 3 && d === 4;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b,c,d; ({a,b} = {c,d} = {a:1,b:2,c:3,d:4}); return a === 1 && b === 2 && c === 3 && d === 4;
}
§throws on null and undefined
?
function(){
var a,b; try { ({a} = null); return false; } catch(e) { if (!(e instanceof TypeError)) return false; } try { ({b} = void undefined); return false; } catch(e) { if (!(e instanceof TypeError)) return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b; try { ({a} = null); return false; } catch(e) { if (!(e instanceof TypeError)) return false; } try { ({b} = void undefined); return false; } catch(e) { if (!(e instanceof TypeError)) return false; } return true;
}
§computed properties
?
function(){
var grault, qux = "corge"; ({ [qux]: grault } = { corge: "garply" }); return grault === "garply";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var grault, qux = "corge"; ({ [qux]: grault } = { corge: "garply" }); return grault === "garply";
}
§nested
?
function(){
var e,f,g,h,i; [e, {x:f, g}] = [9, {x:10}]; ({h, x:[i]} = {h:11, x:[12]}); return e === 9 && f === 10 && g === void undefined && h === 11 && i === 12;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var e,f,g,h,i; [e, {x:f, g}] = [9, {x:10}]; ({h, x:[i]} = {h:11, x:[12]}); return e === 9 && f === 10 && g === void undefined && h === 11 && i === 12;
}
§rest
?
function(){
var a,b,c,d; [a, ...b] = [3, 4, 5]; [c, ...d] = [6]; return a === 3 && b instanceof Array && (b + "") === "4,5" && c === 6 && d instanceof Array && d.length === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b,c,d; [a, ...b] = [3, 4, 5]; [c, ...d] = [6]; return a === 3 && b instanceof Array && (b + "") === "4,5" && c === 6 && d instanceof Array && d.length === 0;
}
§nested rest
?
function(){
var a = [1, 2, 3], first, last; [first, ...[a[2], last]] = a; return first === 1 && last === 3 && (a + "") === "1,2,2";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a = [1, 2, 3], first, last; [first, ...[a[2], last]] = a; return first === 1 && last === 3 && (a + "") === "1,2,2";
}
§empty patterns
?
function(){
[] = [1,2]; ({} = {a:1,b:2}); return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
[] = [1,2]; ({} = {a:1,b:2}); return true;
}
§defaults
?
function(){
var a,b,c,d,e,f; ({a = 1, b = 0, z:c = 3} = {b:2, z:undefined}); [d = 0, e = 5, f = 6] = [4,,undefined]; return a === 1 && b === 2 && c === 3 && d === 4 && e === 5 && f === 6;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var a,b,c,d,e,f; ({a = 1, b = 0, z:c = 3} = {b:2, z:undefined}); [d = 0, e = 5, f = 6] = [4,,undefined]; return a === 1 && b === 2 && c === 3 && d === 4 && e === 5 && f === 6;
}

destructuring, parameters

§with arrays
?
function(){
return function([a, , [b], c]) { return a === 5 && b === 6 && c === void undefined; }([5, null, [6]]);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([a, , [b], c]) { return a === 5 && b === 6 && c === void undefined; }([5, null, [6]]);
}
§with sparse arrays
?
function(){
return function([a, , b]) { return a === void undefined && b === void undefined; }([,,,]);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([a, , b]) { return a === void undefined && b === void undefined; }([,,,]);
}
§with strings
?
function(){
return function([a, b, c]) { return a === "a" && b === "b" && c === void undefined; }("ab");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([a, b, c]) { return a === "a" && b === "b" && c === void undefined; }("ab");
}
§with astral plane strings
?
function(){
return function([c]) { return c === "𠮷"; }("𠮷𠮶");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([c]) { return c === "𠮷"; }("𠮷𠮶");
}
§with generator instances
?
function(){
return function([a, b, c]) { return a === 1 && b === 2 && c === void undefined; }(function*(){ yield 1; yield 2; }());
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([a, b, c]) { return a === 1 && b === 2 && c === void undefined; }(function*(){ yield 1; yield 2; }());
}
§with generic iterables
?
function(){
return function([a, b, c]) { return a === 1 && b === 2 && c === void undefined; }(global.__createIterableObject([1, 2]));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([a, b, c]) { return a === 1 && b === 2 && c === void undefined; }(global.__createIterableObject([1, 2]));
}
§with instances of generic iterables
?
function(){
return function([a, b, c]) { return a === 1 && b === 2 && c === void undefined; }(Object.create(global.__createIterableObject([1, 2])));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([a, b, c]) { return a === 1 && b === 2 && c === void undefined; }(Object.create(global.__createIterableObject([1, 2])));
}
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); (function([a,b]) {}(iter)); return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); (function([a,b]) {}(iter)); return closed;
}
§trailing commas in iterable patterns
?
function(){
return function([a,]) { return a === 1; }([1]);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([a,]) { return a === 1; }([1]);
}
§with objects
?
function(){
return function({c, x:d, e}) { return c === 7 && d === 8 && e === void undefined; }({c:7, x:8});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function({c, x:d, e}) { return c === 7 && d === 8 && e === void undefined; }({c:7, x:8});
}
§object destructuring with primitives
?
function(){
return function({toFixed}, {slice}) { return toFixed === Number.prototype.toFixed && slice === String.prototype.slice; }(2,'');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function({toFixed}, {slice}) { return toFixed === Number.prototype.toFixed && slice === String.prototype.slice; }(2,'');
}
§trailing commas in object patterns
?
function(){
return function({a,}) { return a === 1; }({a:1});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function({a,}) { return a === 1; }({a:1});
}
§throws on null and undefined
?
function(){
try { (function({a}){}(null)); return false; } catch(e) {} try { (function({b}){}(undefined)); return false; } catch(e) {} return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
try { (function({a}){}(null)); return false; } catch(e) {} try { (function({b}){}(undefined)); return false; } catch(e) {} return true;
}
§computed properties
?
function(){
var qux = "corge"; return function({ [qux]: grault }) { return grault === "garply"; }({ corge: "garply" });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var qux = "corge"; return function({ [qux]: grault }) { return grault === "garply"; }({ corge: "garply" });
}
§nested
?
function(){
return function([e, {x:f, g}], {h, x:[i]}) { return e === 9 && f === 10 && g === void undefined && h === 11 && i === 12; }([9, {x:10}],{h:11, x:[12]});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([e, {x:f, g}], {h, x:[i]}) { return e === 9 && f === 10 && g === void undefined && h === 11 && i === 12; }([9, {x:10}],{h:11, x:[12]});
}
§'arguments' interaction
?
function(){
return (function({a, x:b, y:e}, [c, d]) { return arguments[0].a === 1 && arguments[0].x === 2 && !("y" in arguments[0]) && arguments[1] + '' === "3,4"; }({a:1, x:2}, [3, 4]));
}
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return (function({a, x:b, y:e}, [c, d]) { return arguments[0].a === 1 && arguments[0].x === 2 && !("y" in arguments[0]) && arguments[1] + '' === "3,4"; }({a:1, x:2}, [3, 4]));
}
§new Function() support
?
function(){
return new Function("{a, x:b, y:e}","[c, d]", "return a === 1 && b === 2 && c === 3 && " + "d === 4 && e === void undefined;" )({a:1, x:2}, [3, 4]);
}
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return new Function("{a, x:b, y:e}","[c, d]", "return a === 1 && b === 2 && c === 3 && " + "d === 4 && e === void undefined;" )({a:1, x:2}, [3, 4]);
}
§in parameters, function 'length' property
?
function(){
return function({a, b}, [c, d]){}.length === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function({a, b}, [c, d]){}.length === 2;
}
§rest
?
function(){
return function([a, ...b], [c, ...d]) { return a === 3 && b instanceof Array && (b + "") === "4,5" && c === 6 && d instanceof Array && d.length === 0; }([3, 4, 5], [6]);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function([a, ...b], [c, ...d]) { return a === 3 && b instanceof Array && (b + "") === "4,5" && c === 6 && d instanceof Array && d.length === 0; }([3, 4, 5], [6]);
}
§empty patterns
?
function(){
return function ([],{}){ return arguments[0] + '' === "3,4" && arguments[1].x === "foo"; }([3,4],{x:"foo"});
}
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return function ([],{}){ return arguments[0] + '' === "3,4" && arguments[1].x === "foo"; }([3,4],{x:"foo"});
}
§defaults
?
function(){
return (function({a = 1, b = 0, c = 3, x:d = 0, y:e = 5}, [f = 6, g = 0, h = 8]) { return a === 1 && b === 2 && c === 3 && d === 4 && e === 5 && f === 6 && g === 7 && h === 8; }({b:2, c:undefined, x:4},[, 7, undefined]));
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return (function({a = 1, b = 0, c = 3, x:d = 0, y:e = 5}, [f = 6, g = 0, h = 8]) { return a === 1 && b === 2 && c === 3 && d === 4 && e === 5 && f === 6 && g === 7 && h === 8; }({b:2, c:undefined, x:4},[, 7, undefined]));
}
§defaults, separate scope
?
function(){
return (function({a=function(){ return typeof b === 'undefined'; }}){ var b = 1; return a(); }({}));
}
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return (function({a=function(){ return typeof b === 'undefined'; }}){ var b = 1; return a(); }({}));
}
§defaults, new Function() support
?
function(){
return new Function("{a = 1, b = 0, c = 3, x:d = 0, y:e = 5}", "return a === 1 && b === 2 && c === 3 && d === 4 && e === 5;" )({b:2, c:undefined, x:4});
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return new Function("{a = 1, b = 0, c = 3, x:d = 0, y:e = 5}", "return a === 1 && b === 2 && c === 3 && d === 4 && e === 5;" )({b:2, c:undefined, x:4});
}
§aliased defaults, arrow function
?
function(){
return ((a, {b: x = 0, c: y = 3}) => { return a === 1 && x === 2 && y === 3; })(1, {b: 2});
}
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return ((a, {b: x = 0, c: y = 3}) => { return a === 1 && x === 2 && y === 3; })(1, {b: 2});
}
§shorthand defaults, arrow function
?
function(){
return ((a, {b = 0, c = 3}) => { return a === 1 && b === 2 && c === 3; })(1, {b: 2});
}
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
return ((a, {b = 0, c = 3}) => { return a === 1 && b === 2 && c === 3; })(1, {b: 2});
}
§duplicate identifier
?
function(){
try { eval('var d = function d([d]) { return d };'); if (d([true]) !== true) return false; } catch (e) { return !(e instanceof SyntaxError); } try { eval('var f = function f([id, id]) { return id }'); return false; } catch (e) { return e instanceof SyntaxError; }
}
Yes
Yes
Yes
Yes
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Yes
No
No
No
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No
No
function(){
try { eval('var d = function d([d]) { return d };'); if (d([true]) !== true) return false; } catch (e) { return !(e instanceof SyntaxError); } try { eval('var f = function f([id, id]) { return id }'); return false; } catch (e) { return e instanceof SyntaxError; }
}

Unicode code point escapes

§in strings
?
function(){
return '\u{1d306}' === '\ud834\udf06';
}
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
return '\u{1d306}' === '\ud834\udf06';
}
§in identifiers
?
function(){
var \u{102C0} = 2; return \u{102C0} === 2;
}
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var \u{102C0} = 2; return \u{102C0} === 2;
}
§in property key definitions
?
function(){
var o = { \u{102C0} : 2 }; return o['\ud800\udec0'] === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var o = { \u{102C0} : 2 }; return o['\ud800\udec0'] === 2;
}
§in property key accesses
?
function(){
var o = { '\ud800\udec0' : 2 }; return o.\u{102C0} === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var o = { '\ud800\udec0' : 2 }; return o.\u{102C0} === 2;
}

new.target

§in constructors
?
function(){
var passed = false; new function f() { passed = (new.target === f); }(); (function() { passed &= (new.target === void undefined); }()); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Error
Error
Error
Error
Error
Error
function(){
var passed = false; new function f() { passed = (new.target === f); }(); (function() { passed &= (new.target === void undefined); }()); return passed;
}
§assignment is an early error
?
function(){
var passed = false; new function f() { passed = (new.target === f); }(); try { Function("new.target = function(){};"); } catch(e) { return passed; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
function(){
var passed = false; new function f() { passed = (new.target === f); }(); try { Function("new.target = function(){};"); } catch(e) { return passed; }
}

bindings

const

§basic support
?
function(){
const foo = 123; return (foo === 123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
function(){
const foo = 123; return (foo === 123);
}
§is block-scoped
?
function(){
const bar = 123; { const bar = 456; } return bar === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
const bar = 123; { const bar = 456; } return bar === 123;
}
§scope shadow resolution
?
function(){
try { { const bar = 456; } const bar = 123; return bar === 123; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
try { { const bar = 456; } const bar = 123; return bar === 123; } catch(e) { return false; }
}
§cannot be in statements
?
function(){
const bar = 1; try { Function("if(true) const baz = 1;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
function(){
const bar = 1; try { Function("if(true) const baz = 1;")(); } catch(e) { return true; }
}
§redefining a const is an error
?
function(){
const baz = 1; try { Function("const foo = 1; foo = 2;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
function(){
const baz = 1; try { Function("const foo = 1; foo = 2;")(); } catch(e) { return true; }
}
§for loop statement scope
?
function(){
const baz = 1; for(const baz = 0; false;) {} return baz === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
const baz = 1; for(const baz = 0; false;) {} return baz === 1;
}
§for-in loop iteration scope
?
function(){
var scopes = []; for(const i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
Error
Error
Error
function(){
var scopes = []; for(const i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
§for-of loop iteration scope
?
function(){
var scopes = []; for(const i of ['a','b']) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
Error
Error
Error
function(){
var scopes = []; for(const i of ['a','b']) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
§temporal dead zone
?
function(){
var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } const qux = 456; fn(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
function(){
var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } const qux = 456; fn(); return passed;
}
§basic support (strict mode)
?
function(){
"use strict"; const foo = 123; return (foo === 123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
"use strict"; const foo = 123; return (foo === 123);
}
§is block-scoped (strict mode)
?
function(){
'use strict'; const bar = 123; { const bar = 456; } return bar === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; const bar = 123; { const bar = 456; } return bar === 123;
}
§scope shadow resolution (strict mode)
?
function(){
'use strict'; try { { const bar = 456; } const bar = 123; return bar === 123; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; try { { const bar = 456; } const bar = 123; return bar === 123; } catch(e) { return false; }
}
§cannot be in statements (strict mode)
?
function(){
'use strict'; const bar = 1; try { Function("'use strict'; if(true) const baz = 1;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; const bar = 1; try { Function("'use strict'; if(true) const baz = 1;")(); } catch(e) { return true; }
}
§redefining a const (strict mode)
?
function(){
'use strict'; const baz = 1; try { Function("'use strict'; const foo = 1; foo = 2;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; const baz = 1; try { Function("'use strict'; const foo = 1; foo = 2;")(); } catch(e) { return true; }
}
§for loop statement scope (strict mode)
?
function(){
'use strict'; const baz = 1; for(const baz = 0; false;) {} return baz === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; const baz = 1; for(const baz = 0; false;) {} return baz === 1;
}
§for-in loop iteration scope (strict mode)
?
function(){
'use strict'; var scopes = []; for(const i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
'use strict'; var scopes = []; for(const i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
§for-of loop iteration scope (strict mode)
?
function(){
'use strict'; var scopes = []; for(const i of ['a','b']) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
'use strict'; var scopes = []; for(const i of ['a','b']) { scopes.push(function(){ return i; }); } return (scopes[0]() === "a" && scopes[1]() === "b");
}
§temporal dead zone (strict mode)
?
function(){
'use strict'; var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } const qux = 456; fn(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } const qux = 456; fn(); return passed;
}

let

§basic support
?
function(){
let foo = 123; return (foo === 123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
let foo = 123; return (foo === 123);
}
§is block-scoped
?
function(){
let bar = 123; { let bar = 456; } return bar === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
let bar = 123; { let bar = 456; } return bar === 123;
}
§scope shadow resolution
?
function(){
try { { let bar = 456; } let bar = 123; return bar === 123; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
try { { let bar = 456; } let bar = 123; return bar === 123; } catch(e) { return false; }
}
§cannot be in statements
?
function(){
let bar = 1; try { Function("if(true) let baz = 1;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
let bar = 1; try { Function("if(true) let baz = 1;")(); } catch(e) { return true; }
}
§for loop statement scope
?
function(){
let baz = 1; for(let baz = 0; false;) {} return baz === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
let baz = 1; for(let baz = 0; false;) {} return baz === 1;
}
§temporal dead zone
?
function(){
var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } let qux = 456; fn(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } let qux = 456; fn(); return passed;
}
§for/for-in loop iteration scope
?
function(){
let scopes = []; for(let i = 0; i < 2; i++) { scopes.push(function(){ return i; }); } let passed = (scopes[0]() === 0 && scopes[1]() === 1); scopes = []; for(let i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } passed &= (scopes[0]() === "a" && scopes[1]() === "b"); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
let scopes = []; for(let i = 0; i < 2; i++) { scopes.push(function(){ return i; }); } let passed = (scopes[0]() === 0 && scopes[1]() === 1); scopes = []; for(let i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } passed &= (scopes[0]() === "a" && scopes[1]() === "b"); return passed;
}
§for-in loop binding shadowing parameter
?
function(){
try { Function("function f(e) { for (let e in {}) e }"); return true; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
function(){
try { Function("function f(e) { for (let e in {}) e }"); return true; } catch(e) { return false; }
}
§basic support (strict mode)
?
function(){
'use strict'; let foo = 123; return (foo === 123);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; let foo = 123; return (foo === 123);
}
§is block-scoped (strict mode)
?
function(){
'use strict'; let bar = 123; { let bar = 456; } return bar === 123;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; let bar = 123; { let bar = 456; } return bar === 123;
}
§scope shadow resolution (strict mode)
?
function(){
'use strict'; try { { let bar = 456; } let bar = 123; return bar === 123; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; try { { let bar = 456; } let bar = 123; return bar === 123; } catch(e) { return false; }
}
§cannot be in statements (strict mode)
?
function(){
'use strict'; let bar = 1; try { Function("'use strict'; if(true) let baz = 1;")(); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; let bar = 1; try { Function("'use strict'; if(true) let baz = 1;")(); } catch(e) { return true; }
}
§for loop statement scope (strict mode)
?
function(){
'use strict'; let baz = 1; for(let baz = 0; false;) {} return baz === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; let baz = 1; for(let baz = 0; false;) {} return baz === 1;
}
§temporal dead zone (strict mode)
?
function(){
'use strict'; var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } let qux = 456; fn(); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; var passed = (function(){ try { qux; } catch(e) { return true; }}()); function fn() { passed &= qux === 456; } let qux = 456; fn(); return passed;
}
§for/for-in loop iteration scope (strict mode)
?
function(){
'use strict'; let scopes = []; for(let i = 0; i < 2; i++) { scopes.push(function(){ return i; }); } let passed = (scopes[0]() === 0 && scopes[1]() === 1); scopes = []; for(let i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } passed &= (scopes[0]() === "a" && scopes[1]() === "b"); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
No
function(){
'use strict'; let scopes = []; for(let i = 0; i < 2; i++) { scopes.push(function(){ return i; }); } let passed = (scopes[0]() === 0 && scopes[1]() === 1); scopes = []; for(let i in { a:1, b:1 }) { scopes.push(function(){ return i; }); } passed &= (scopes[0]() === "a" && scopes[1]() === "b"); return passed;
}
§for-in loop binding shadowing parameter (strict mode)
?
function(){
try { Function("'use strict'; function f(e) { for (let e in {}) e }"); return true; } catch(e) { return false; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
function(){
try { Function("'use strict'; function f(e) { for (let e in {}) e }"); return true; } catch(e) { return false; }
}

§block-level function declaration
?
function(){
'use strict'; if (f() !== 1) return false; function f() { return 1; } { if (f() !== 2) return false; function f() { return 2; } if (f() !== 2) return false; } if (f() !== 1) return false; return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Flag
function(){
'use strict'; if (f() !== 1) return false; function f() { return 1; } { if (f() !== 2) return false; function f() { return 2; } if (f() !== 2) return false; } if (f() !== 1) return false; return true;
}

functions

arrow functions

§0 parameters
?
function(){
return (() => 5)() === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
return (() => 5)() === 5;
}
§1 parameter, no brackets
?
function(){
var b = x => x + "foo"; return (b("fee fie foe ") === "fee fie foe foo");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var b = x => x + "foo"; return (b("fee fie foe ") === "fee fie foe foo");
}
§multiple parameters
?
function(){
var c = (v, w, x, y, z) => "" + v + w + x + y + z; return (c(6, 5, 4, 3, 2) === "65432");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var c = (v, w, x, y, z) => "" + v + w + x + y + z; return (c(6, 5, 4, 3, 2) === "65432");
}
§lexical "this" binding
?
function(){
var d = { x : "bar", y : function() { return z => this.x + z; }}.y(); var e = { x : "baz", y : d }; return d("ley") === "barley" && e.y("ley") === "barley";
}
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
function(){
var d = { x : "bar", y : function() { return z => this.x + z; }}.y(); var e = { x : "baz", y : d }; return d("ley") === "barley" && e.y("ley") === "barley";
}
§"this" unchanged by call or apply
?
function(){
var d = { x : "foo", y : function() { return () => this.x; }}; var e = { x : "bar" }; return d.y().call(e) === "foo" && d.y().apply(e) === "foo";
}
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Error
No
Error
Error
function(){
var d = { x : "foo", y : function() { return () => this.x; }}; var e = { x : "bar" }; return d.y().call(e) === "foo" && d.y().apply(e) === "foo";
}
§can't be bound, can be curried
?
function(){
var d = { x : "bar", y : function() { return z => this.x + z; }}; var e = { x : "baz" }; return d.y().bind(e, "ley")() === "barley";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
function(){
var d = { x : "bar", y : function() { return z => this.x + z; }}; var e = { x : "baz" }; return d.y().bind(e, "ley")() === "barley";
}
§lexical "arguments" binding
?
function(){
var f = (function() { return z => arguments[0]; }(5)); return f(6) === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
function(){
var f = (function() { return z => arguments[0]; }(5)); return f(6) === 5;
}
§no line break between params and =>
?
function(){
return (() => { try { Function("x\n => 2")(); } catch(e) { return true; } })();
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
function(){
return (() => { try { Function("x\n => 2")(); } catch(e) { return true; } })();
}
§correct precedence
?
function(){
return (() => { try { Function("0 || () => 2")(); } catch(e) { return true; } })();
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
No
Error
Error
function(){
return (() => { try { Function("0 || () => 2")(); } catch(e) { return true; } })();
}
§no "prototype" property
?
function(){
var a = () => 5; return !a.hasOwnProperty("prototype");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
No
Error
Error
function(){
var a = () => 5; return !a.hasOwnProperty("prototype");
}
§lexical "super" binding in constructors
?
function(){
var received; class B { constructor (arg) { received = arg; } } class C extends B { constructor () { var callSuper = () => super('foo'); callSuper(); } } return new C instanceof C && received === 'foo'
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var received; class B { constructor (arg) { received = arg; } } class C extends B { constructor () { var callSuper = () => super('foo'); callSuper(); } } return new C instanceof C && received === 'foo'
}
§lexical "super" binding in methods
?
function(){
class B { qux() { return "quux"; } } class C extends B { baz() { return x => super.qux(); } } var arrow = new C().baz(); return arrow() === "quux";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class B { qux() { return "quux"; } } class C extends B { baz() { return x => super.qux(); } } var arrow = new C().baz(); return arrow() === "quux";
}
§lexical "new.target" binding
?
function(){
function C() { return x => new.target; } return new C()() === C && C()() === void undefined;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
function(){
function C() { return x => new.target; } return new C()() === C && C()() === void undefined;
}

class

§class statement
?
function(){
class C {} return typeof C === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C {} return typeof C === "function";
}
§is block-scoped
?
function(){
class C {} var c1 = C; { class C {} var c2 = C; } return C === c1;
}
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C {} var c1 = C; { class C {} var c2 = C; } return C === c1;
}
§class expression
?
function(){
return typeof class C {} === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
return typeof class C {} === "function";
}
§anonymous class
?
function(){
return typeof class {} === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
return typeof class {} === "function";
}
§constructor
?
function(){
class C { constructor() { this.x = 1; } } return C.prototype.constructor === C && new C().x === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { constructor() { this.x = 1; } } return C.prototype.constructor === C && new C().x === 1;
}
§prototype methods
?
function(){
class C { method() { return 2; } } return typeof C.prototype.method === "function" && new C().method() === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { method() { return 2; } } return typeof C.prototype.method === "function" && new C().method() === 2;
}
§string-keyed methods
?
function(){
class C { "foo bar"() { return 2; } } return typeof C.prototype["foo bar"] === "function" && new C()["foo bar"]() === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { "foo bar"() { return 2; } } return typeof C.prototype["foo bar"] === "function" && new C()["foo bar"]() === 2;
}
§computed prototype methods
?
function(){
var foo = "method"; class C { [foo]() { return 2; } } return typeof C.prototype.method === "function" && new C().method() === 2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var foo = "method"; class C { [foo]() { return 2; } } return typeof C.prototype.method === "function" && new C().method() === 2;
}
§optional semicolons
?
function(){
class C { ; method() { return 2; }; method2() { return 2; } method3() { return 2; }; } return typeof C.prototype.method === "function" && typeof C.prototype.method2 === "function" && typeof C.prototype.method3 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { ; method() { return 2; }; method2() { return 2; } method3() { return 2; }; } return typeof C.prototype.method === "function" && typeof C.prototype.method2 === "function" && typeof C.prototype.method3 === "function";
}
§static methods
?
function(){
class C { static method() { return 3; } } return typeof C.method === "function" && C.method() === 3;
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { static method() { return 3; } } return typeof C.method === "function" && C.method() === 3;
}
§computed static methods
?
function(){
var foo = "method"; class C { static [foo]() { return 3; } } return typeof C.method === "function" && C.method() === 3;
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var foo = "method"; class C { static [foo]() { return 3; } } return typeof C.method === "function" && C.method() === 3;
}
§accessor properties
?
function(){
var baz = false; class C { get foo() { return "foo"; } set bar(x) { baz = x; } } new C().bar = true; return new C().foo === "foo" && baz;
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var baz = false; class C { get foo() { return "foo"; } set bar(x) { baz = x; } } new C().bar = true; return new C().foo === "foo" && baz;
}
§computed accessor properties
?
function(){
var garply = "foo", grault = "bar", baz = false; class C { get [garply]() { return "foo"; } set [grault](x) { baz = x; } } new C().bar = true; return new C().foo === "foo" && baz;
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var garply = "foo", grault = "bar", baz = false; class C { get [garply]() { return "foo"; } set [grault](x) { baz = x; } } new C().bar = true; return new C().foo === "foo" && baz;
}
§static accessor properties
?
function(){
var baz = false; class C { static get foo() { return "foo"; } static set bar(x) { baz = x; } } C.bar = true; return C.foo === "foo" && baz;
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var baz = false; class C { static get foo() { return "foo"; } static set bar(x) { baz = x; } } C.bar = true; return C.foo === "foo" && baz;
}
§computed static accessor properties
?
function(){
var garply = "foo", grault = "bar", baz = false; class C { static get [garply]() { return "foo"; } static set [grault](x) { baz = x; } } C.bar = true; return C.foo === "foo" && baz;
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var garply = "foo", grault = "bar", baz = false; class C { static get [garply]() { return "foo"; } static set [grault](x) { baz = x; } } C.bar = true; return C.foo === "foo" && baz;
}
§class name is lexically scoped
?
function(){
class C { method() { return typeof C === "function"; } } var M = C.prototype.method; C = void undefined; return C === void undefined && M();
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { method() { return typeof C === "function"; } } var M = C.prototype.method; C = void undefined; return C === void undefined && M();
}
§computed names, temporal dead zone
?
function(){
try { var B = class C { [C](){} } } catch(e) { return true; }
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
try { var B = class C { [C](){} } } catch(e) { return true; }
}
§methods aren't enumerable
?
function(){
class C { foo() {} static bar() {} } return !C.prototype.propertyIsEnumerable("foo") && !C.propertyIsEnumerable("bar");
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { foo() {} static bar() {} } return !C.prototype.propertyIsEnumerable("foo") && !C.propertyIsEnumerable("bar");
}
§implicit strict mode
?
function(){
class C { static method() { return this === void undefined; } } return (0,C.method)();
}
Yes
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { static method() { return this === void undefined; } } return (0,C.method)();
}
§constructor requires new
?
function(){
class C {} try { C(); } catch(e) { return true; }
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C {} try { C(); } catch(e) { return true; }
}
§extends
?
function(){
class B {} class C extends B {} return new C() instanceof B && B.isPrototypeOf(C);
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class B {} class C extends B {} return new C() instanceof B && B.isPrototypeOf(C);
}
§extends expressions
?
function(){
var B; class C extends (B = class {}) {} return new C() instanceof B && B.isPrototypeOf(C);
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var B; class C extends (B = class {}) {} return new C() instanceof B && B.isPrototypeOf(C);
}
§extends null
?
function(){
class C extends null { constructor() { return Object.create(null); } } return Function.prototype.isPrototypeOf(C) && Object.getPrototypeOf(C.prototype) === null;
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C extends null { constructor() { return Object.create(null); } } return Function.prototype.isPrototypeOf(C) && Object.getPrototypeOf(C.prototype) === null;
}
§new.target
?
function(){
var passed = false; new function f() { passed = new.target === f; }(); class A { constructor() { passed &= new.target === B; } } class B extends A {} new B(); return passed;
}
Yes
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Yes
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Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var passed = false; new function f() { passed = new.target === f; }(); class A { constructor() { passed &= new.target === B; } } class B extends A {} new B(); return passed;
}

super

§statement in constructors
?
function(){
var passed = false; class B { constructor(a) { passed = (a === "barbaz"); } } class C extends B { constructor(a) { super("bar" + a); } } new C("baz"); return passed;
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var passed = false; class B { constructor(a) { passed = (a === "barbaz"); } } class C extends B { constructor(a) { super("bar" + a); } } new C("baz"); return passed;
}
§expression in constructors
?
function(){
class B { constructor(a) { return ["foo" + a]; } } class C extends B { constructor(a) { return super("bar" + a); } } return new C("baz")[0] === "foobarbaz";
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class B { constructor(a) { return ["foo" + a]; } } class C extends B { constructor(a) { return super("bar" + a); } } return new C("baz")[0] === "foobarbaz";
}
§in methods, property access
?
function(){
class B {} B.prototype.qux = "foo"; B.prototype.corge = "baz"; class C extends B { quux(a) { return super.qux + a + super["corge"]; } } C.prototype.qux = "garply"; return new C().quux("bar") === "foobarbaz";
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class B {} B.prototype.qux = "foo"; B.prototype.corge = "baz"; class C extends B { quux(a) { return super.qux + a + super["corge"]; } } C.prototype.qux = "garply"; return new C().quux("bar") === "foobarbaz";
}
§in methods, method calls
?
function(){
class B { qux(a) { return "foo" + a; } } class C extends B { qux(a) { return super.qux("bar" + a); } } return new C().qux("baz") === "foobarbaz";
}
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Error
Flag
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function(){
class B { qux(a) { return "foo" + a; } } class C extends B { qux(a) { return super.qux("bar" + a); } } return new C().qux("baz") === "foobarbaz";
}
§method calls use correct "this" binding
?
function(){
class B { qux(a) { return this.foo + a; } } class C extends B { qux(a) { return super.qux("bar" + a); } } var obj = new C(); obj.foo = "foo"; return obj.qux("baz") === "foobarbaz";
}
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class B { qux(a) { return this.foo + a; } } class C extends B { qux(a) { return super.qux("bar" + a); } } var obj = new C(); obj.foo = "foo"; return obj.qux("baz") === "foobarbaz";
}
§constructor calls use correct "new.target" binding
?
function(){
var passed; class B { constructor() { passed = (new.target === C); } } class C extends B { constructor() { super(); } } new C(); return passed;
}
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var passed; class B { constructor() { passed = (new.target === C); } } class C extends B { constructor() { super(); } } new C(); return passed;
}
§is statically bound
?
function(){
class B { qux() { return "bar"; } } class C extends B { qux() { return super.qux() + this.corge; } } var obj = { qux: C.prototype.qux, corge: "ley" }; return obj.qux() === "barley";
}
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class B { qux() { return "bar"; } } class C extends B { qux() { return super.qux() + this.corge; } } var obj = { qux: C.prototype.qux, corge: "ley" }; return obj.qux() === "barley";
}
§super() invokes the correct constructor
?
function(){
// checks that super() is *not* a synonym of super.constructor() var passed; class B { constructor() { passed = true; } }; B.prototype.constructor = function () { passed = false; }; class C extends B { }; new C; return passed;
}
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Error
Flag
Error
Error
Error
Error
Error
Error
function(){
// checks that super() is *not* a synonym of super.constructor() var passed; class B { constructor() { passed = true; } }; B.prototype.constructor = function () { passed = false; }; class C extends B { }; new C; return passed;
}

generators

§basic functionality
?
function(){
function * generator(){ yield 5; yield 6; }; var iterator = generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
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Error
Flag
Error
Error
function(){
function * generator(){ yield 5; yield 6; }; var iterator = generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§generator function expressions
?
function(){
var generator = function * (){ yield 5; yield 6; }; var iterator = generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
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Error
Flag
Error
Error
function(){
var generator = function * (){ yield 5; yield 6; }; var iterator = generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§correct "this" binding
?
function(){
function * generator(){ yield this.x; yield this.y; }; var iterator = { g: generator, x: 5, y: 6 }.g(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
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Error
Flag
Error
Error
function(){
function * generator(){ yield this.x; yield this.y; }; var iterator = { g: generator, x: 5, y: 6 }.g(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§can't use "this" with new
?
function(){
function * generator(){ yield this.x; yield this.y; }; try { (new generator()).next(); } catch (e) { return true; }
}
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Error
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Error
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function(){
function * generator(){ yield this.x; yield this.y; }; try { (new generator()).next(); } catch (e) { return true; }
}
§sending
?
function(){
var sent; function * generator(){ sent = [yield 5, yield 6]; }; var iterator = generator(); iterator.next(); iterator.next("foo"); iterator.next("bar"); return sent[0] === "foo" && sent[1] === "bar";
}
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Error
Flag
Error
Error
function(){
var sent; function * generator(){ sent = [yield 5, yield 6]; }; var iterator = generator(); iterator.next(); iterator.next("foo"); iterator.next("bar"); return sent[0] === "foo" && sent[1] === "bar";
}
§%GeneratorPrototype%
?
function(){
function * generatorFn(){} var ownProto = Object.getPrototypeOf(generatorFn()); var passed = ownProto === generatorFn.prototype; var sharedProto = Object.getPrototypeOf(ownProto); passed &= sharedProto !== Object.prototype && sharedProto === Object.getPrototypeOf(function*(){}.prototype) && sharedProto.hasOwnProperty('next'); return passed;
}
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Error
Flag
Error
Error
function(){
function * generatorFn(){} var ownProto = Object.getPrototypeOf(generatorFn()); var passed = ownProto === generatorFn.prototype; var sharedProto = Object.getPrototypeOf(ownProto); passed &= sharedProto !== Object.prototype && sharedProto === Object.getPrototypeOf(function*(){}.prototype) && sharedProto.hasOwnProperty('next'); return passed;
}
§%GeneratorPrototype% prototype chain
?
function(){
function * generatorFn(){} var g = generatorFn(); var ownProto = Object.getPrototypeOf(g); var passed = ownProto === generatorFn.prototype; var sharedProto = Object.getPrototypeOf(ownProto); var iterProto = Object.getPrototypeOf(sharedProto); passed &= iterProto.hasOwnProperty(Symbol.iterator) && !sharedProto .hasOwnProperty(Symbol.iterator) && !ownProto .hasOwnProperty(Symbol.iterator) && g[Symbol.iterator]() === g; return passed;
}
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Error
No
Error
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function(){
function * generatorFn(){} var g = generatorFn(); var ownProto = Object.getPrototypeOf(g); var passed = ownProto === generatorFn.prototype; var sharedProto = Object.getPrototypeOf(ownProto); var iterProto = Object.getPrototypeOf(sharedProto); passed &= iterProto.hasOwnProperty(Symbol.iterator) && !sharedProto .hasOwnProperty(Symbol.iterator) && !ownProto .hasOwnProperty(Symbol.iterator) && g[Symbol.iterator]() === g; return passed;
}
§%GeneratorPrototype%.constructor
?
function(){
function * g (){} var iterator = new g.constructor("a","b","c","yield a; yield b; yield c;")(5,6,7); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; passed &= g.constructor === (function*(){}).constructor; return passed;
}
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Error
Flag
Error
Error
function(){
function * g (){} var iterator = new g.constructor("a","b","c","yield a; yield b; yield c;")(5,6,7); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; passed &= g.constructor === (function*(){}).constructor; return passed;
}
§%GeneratorPrototype%.throw
?
function(){
var passed = false; function * generator(){ try { yield 5; yield 6; } catch(e) { passed = (e === "foo"); } }; var iterator = generator(); iterator.next(); iterator.throw("foo"); return passed;
}
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Error
Flag
Error
Error
function(){
var passed = false; function * generator(){ try { yield 5; yield 6; } catch(e) { passed = (e === "foo"); } }; var iterator = generator(); iterator.next(); iterator.throw("foo"); return passed;
}
§%GeneratorPrototype%.return
?
function(){
function * generator(){ yield 5; yield 6; }; var iterator = generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.return("quxquux"); passed &= item.value === "quxquux" && item.done === true; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
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Error
Error
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Error
function(){
function * generator(){ yield 5; yield 6; }; var iterator = generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.return("quxquux"); passed &= item.value === "quxquux" && item.done === true; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§yield operator precedence
?
function(){
var passed; function * generator(){ passed = yield 0 ? true : false; }; var iterator = generator(); iterator.next(); iterator.next(true); return passed;
}
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var passed; function * generator(){ passed = yield 0 ? true : false; }; var iterator = generator(); iterator.next(); iterator.next(true); return passed;
}
§yield *, arrays
?
function(){
var iterator = (function * generator() { yield * [5, 6]; }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var iterator = (function * generator() { yield * [5, 6]; }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§yield *, sparse arrays
?
function(){
var iterator = (function * generator() { yield * [,,]; }()); var item = iterator.next(); var passed = item.value === void undefined && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var iterator = (function * generator() { yield * [,,]; }()); var item = iterator.next(); var passed = item.value === void undefined && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§yield *, strings
?
function(){
var iterator = (function * generator() { yield * "56"; }()); var item = iterator.next(); var passed = item.value === "5" && item.done === false; item = iterator.next(); passed &= item.value === "6" && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var iterator = (function * generator() { yield * "56"; }()); var item = iterator.next(); var passed = item.value === "5" && item.done === false; item = iterator.next(); passed &= item.value === "6" && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§yield *, astral plane strings
?
function(){
var iterator = (function * generator() { yield * "𠮷𠮶"; }()); var item = iterator.next(); var passed = item.value === "𠮷" && item.done === false; item = iterator.next(); passed &= item.value === "𠮶" && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var iterator = (function * generator() { yield * "𠮷𠮶"; }()); var item = iterator.next(); var passed = item.value === "𠮷" && item.done === false; item = iterator.next(); passed &= item.value === "𠮶" && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§yield *, generator instances
?
function(){
var iterator = (function * generator() { yield * (function*(){ yield 5; yield 6; yield 7; }()); }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var iterator = (function * generator() { yield * (function*(){ yield 5; yield 6; yield 7; }()); }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§yield *, generic iterables
?
function(){
var iterator = (function * generator() { yield * global.__createIterableObject([5, 6, 7]); }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
Yes
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Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var iterator = (function * generator() { yield * global.__createIterableObject([5, 6, 7]); }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§yield *, instances of iterables
?
function(){
var iterator = (function * generator() { yield * Object.create(__createIterableObject([5, 6, 7])); }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var iterator = (function * generator() { yield * Object.create(__createIterableObject([5, 6, 7])); }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === 7 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§yield * on non-iterables is a runtime error
?
function(){
var iterator = (function * generator() { yield * [5]; }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; iterator = (function * generator() { yield * 5; }()); try { iterator.next(); } catch (e) { return passed; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
function(){
var iterator = (function * generator() { yield * [5]; }()); var item = iterator.next(); var passed = item.value === 5 && item.done === false; iterator = (function * generator() { yield * 5; }()); try { iterator.next(); } catch (e) { return passed; }
}
§yield *, iterator closing
?
function(){
var closed = ''; var iter = __createIterableObject([1, 2, 3], { 'return': function(){ closed += 'a'; return {done: true}; } }); var gen = (function* generator(){ try { yield *iter; } finally { closed += 'b'; } })(); gen.next(); gen['return'](); return closed === 'ab';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var closed = ''; var iter = __createIterableObject([1, 2, 3], { 'return': function(){ closed += 'a'; return {done: true}; } }); var gen = (function* generator(){ try { yield *iter; } finally { closed += 'b'; } })(); gen.next(); gen['return'](); return closed === 'ab';
}
§yield *, iterator closing via throw()
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'throw': undefined, 'return': function() { closed = true; return {done: true}; } }); var gen = (function*(){ try { yield *iter; } catch(e){} })(); gen.next(); gen['throw'](); return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Error
No
Error
Error
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'throw': undefined, 'return': function() { closed = true; return {done: true}; } }); var gen = (function*(){ try { yield *iter; } catch(e){} })(); gen.next(); gen['throw'](); return closed;
}
§shorthand generator methods
?
function(){
var o = { * generator() { yield 5; yield 6; } }; var iterator = o.generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var o = { * generator() { yield 5; yield 6; } }; var iterator = o.generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§string-keyed shorthand generator methods
?
function(){
var o = { * "foo bar"() { yield 5; yield 6; } }; var iterator = o["foo bar"](); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var o = { * "foo bar"() { yield 5; yield 6; } }; var iterator = o["foo bar"](); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§computed shorthand generators
?
function(){
var garply = "generator"; var o = { * [garply] () { yield 5; yield 6; } }; var iterator = o.generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var garply = "generator"; var o = { * [garply] () { yield 5; yield 6; } }; var iterator = o.generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§shorthand generator methods, classes
?
function(){
class C { * generator() { yield 5; yield 6; } }; var iterator = new C().generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { * generator() { yield 5; yield 6; } }; var iterator = new C().generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§computed shorthand generators, classes
?
function(){
var garply = "generator"; class C { * [garply] () { yield 5; yield 6; } } var iterator = new C().generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
var garply = "generator"; class C { * [garply] () { yield 5; yield 6; } } var iterator = new C().generator(); var item = iterator.next(); var passed = item.value === 5 && item.done === false; item = iterator.next(); passed &= item.value === 6 && item.done === false; item = iterator.next(); passed &= item.value === void undefined && item.done === true; return passed;
}
§shorthand generators can't be constructors
?
function(){
class C { * generator() { yield 5; yield 6; } }; try { Function("class D { * constructor() { return {}; } }"); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { * generator() { yield 5; yield 6; } }; try { Function("class D { * constructor() { return {}; } }"); } catch(e) { return true; }
}

built-ins

typed arrays

§Int8Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Int8Array(buffer); view[0] = 0x80; return view[0] === -0x80;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
function(){
var buffer = new ArrayBuffer(64); var view = new Int8Array(buffer); view[0] = 0x80; return view[0] === -0x80;
}
§Uint8Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Uint8Array(buffer); view[0] = 0x100; return view[0] === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
function(){
var buffer = new ArrayBuffer(64); var view = new Uint8Array(buffer); view[0] = 0x100; return view[0] === 0;
}
§Uint8ClampedArray
?
function(){
var buffer = new ArrayBuffer(64); var view = new Uint8ClampedArray(buffer); view[0] = 0x100; return view[0] === 0xFF;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
function(){
var buffer = new ArrayBuffer(64); var view = new Uint8ClampedArray(buffer); view[0] = 0x100; return view[0] === 0xFF;
}
§Int16Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Int16Array(buffer); view[0] = 0x8000; return view[0] === -0x8000;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
function(){
var buffer = new ArrayBuffer(64); var view = new Int16Array(buffer); view[0] = 0x8000; return view[0] === -0x8000;
}
§Uint16Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Uint16Array(buffer); view[0] = 0x10000; return view[0] === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
function(){
var buffer = new ArrayBuffer(64); var view = new Uint16Array(buffer); view[0] = 0x10000; return view[0] === 0;
}
§Int32Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Int32Array(buffer); view[0] = 0x80000000; return view[0] === -0x80000000;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
function(){
var buffer = new ArrayBuffer(64); var view = new Int32Array(buffer); view[0] = 0x80000000; return view[0] === -0x80000000;
}
§Uint32Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Uint32Array(buffer); view[0] = 0x100000000; return view[0] === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
function(){
var buffer = new ArrayBuffer(64); var view = new Uint32Array(buffer); view[0] = 0x100000000; return view[0] === 0;
}
§Float32Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Float32Array(buffer); view[0] = 0.1; return view[0] === 0.10000000149011612;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new Float32Array(buffer); view[0] = 0.1; return view[0] === 0.10000000149011612;
}
§Float64Array
?
function(){
var buffer = new ArrayBuffer(64); var view = new Float64Array(buffer); view[0] = 0.1; return view[0] === 0.1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new Float64Array(buffer); view[0] = 0.1; return view[0] === 0.1;
}
§DataView (Int8)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setInt8 (0, 0x80); return view.getInt8(0) === -0x80;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setInt8 (0, 0x80); return view.getInt8(0) === -0x80;
}
§DataView (Uint8)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setUint8(0, 0x100); return view.getUint8(0) === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setUint8(0, 0x100); return view.getUint8(0) === 0;
}
§DataView (Int16)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setInt16(0, 0x8000); return view.getInt16(0) === -0x8000;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setInt16(0, 0x8000); return view.getInt16(0) === -0x8000;
}
§DataView (Uint16)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setUint16(0, 0x10000); return view.getUint16(0) === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setUint16(0, 0x10000); return view.getUint16(0) === 0;
}
§DataView (Int32)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setInt32(0, 0x80000000); return view.getInt32(0) === -0x80000000;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setInt32(0, 0x80000000); return view.getInt32(0) === -0x80000000;
}
§DataView (Uint32)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setUint32(0, 0x100000000); return view.getUint32(0) === 0;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setUint32(0, 0x100000000); return view.getUint32(0) === 0;
}
§DataView (Float32)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setFloat32(0, 0.1); return view.getFloat32(0) === 0.10000000149011612;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setFloat32(0, 0.1); return view.getFloat32(0) === 0.10000000149011612;
}
§DataView (Float64)
?
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setFloat64(0, 0.1); return view.getFloat64(0) === 0.1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
function(){
var buffer = new ArrayBuffer(64); var view = new DataView(buffer); view.setFloat64(0, 0.1); return view.getFloat64(0) === 0.1;
}
§ArrayBuffer[Symbol.species]
?
function(){
return typeof ArrayBuffer[Symbol.species] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
function(){
return typeof ArrayBuffer[Symbol.species] === 'function';
}
§constructors require new
?
function(){
var buffer = new ArrayBuffer(64); var constructors = [ 'ArrayBuffer', 'DataView', 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array', 'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array' ]; return constructors.every(function (constructor) { try { if (constructor in global) { global[constructor](constructor === "ArrayBuffer" ? 64 : buffer); } return false; } catch(e) { return true; } });
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
var buffer = new ArrayBuffer(64); var constructors = [ 'ArrayBuffer', 'DataView', 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array', 'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array' ]; return constructors.every(function (constructor) { try { if (constructor in global) { global[constructor](constructor === "ArrayBuffer" ? 64 : buffer); } return false; } catch(e) { return true; } });
}
§constructors accept generic iterables
?
function(){
var constructors = [ 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array', 'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array' ]; for(var i = 0; i < constructors.length; i++){ var arr = new global[constructors[i]](__createIterableObject([1, 2, 3])); if(arr.length !== 3 || arr[0] !== 1 || arr[1] !== 2 || arr[2] !== 3)return false; } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
var constructors = [ 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array', 'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array' ]; for(var i = 0; i < constructors.length; i++){ var arr = new global[constructors[i]](__createIterableObject([1, 2, 3])); if(arr.length !== 3 || arr[0] !== 1 || arr[1] !== 2 || arr[2] !== 3)return false; } return true;
}
§correct prototype chains
?
function(){
var constructors = [ 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array', 'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array' ]; var constructor = Object.getPrototypeOf(Int8Array); var prototype = Object.getPrototypeOf(Int8Array.prototype); if(constructor === Function.prototype || prototype === Object.prototype)return false; for(var i = 0; i < constructors.length; i+=1) { if (!(constructors[i] in global && Object.getPrototypeOf(global[constructors[i]]) === constructor && Object.getPrototypeOf(global[constructors[i]].prototype) === prototype && Object.getOwnPropertyNames(global[constructors[i]].prototype).sort() + '' === "BYTES_PER_ELEMENT,constructor")) { return false; } } return true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
function(){
var constructors = [ 'Int8Array', 'Uint8Array', 'Uint8ClampedArray', 'Int16Array', 'Uint16Array', 'Int32Array', 'Uint32Array', 'Float32Array', 'Float64Array' ]; var constructor = Object.getPrototypeOf(Int8Array); var prototype = Object.getPrototypeOf(Int8Array.prototype); if(constructor === Function.prototype || prototype === Object.prototype)return false; for(var i = 0; i < constructors.length; i+=1) { if (!(constructors[i] in global && Object.getPrototypeOf(global[constructors[i]]) === constructor && Object.getPrototypeOf(global[constructors[i]].prototype) === prototype && Object.getOwnPropertyNames(global[constructors[i]].prototype).sort() + '' === "BYTES_PER_ELEMENT,constructor")) { return false; } } return true;
}
§%TypedArray%.from
?
function(){
return typeof Int8Array.from === "function" && typeof Uint8Array.from === "function" && typeof Uint8ClampedArray.from === "function" && typeof Int16Array.from === "function" && typeof Uint16Array.from === "function" && typeof Int32Array.from === "function" && typeof Uint32Array.from === "function" && typeof Float32Array.from === "function" && typeof Float64Array.from === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.from === "function" && typeof Uint8Array.from === "function" && typeof Uint8ClampedArray.from === "function" && typeof Int16Array.from === "function" && typeof Uint16Array.from === "function" && typeof Int32Array.from === "function" && typeof Uint32Array.from === "function" && typeof Float32Array.from === "function" && typeof Float64Array.from === "function";
}
§%TypedArray%.of
?
function(){
return typeof Int8Array.of === "function" && typeof Uint8Array.of === "function" && typeof Uint8ClampedArray.of === "function" && typeof Int16Array.of === "function" && typeof Uint16Array.of === "function" && typeof Int32Array.of === "function" && typeof Uint32Array.of === "function" && typeof Float32Array.of === "function" && typeof Float64Array.of === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.of === "function" && typeof Uint8Array.of === "function" && typeof Uint8ClampedArray.of === "function" && typeof Int16Array.of === "function" && typeof Uint16Array.of === "function" && typeof Int32Array.of === "function" && typeof Uint32Array.of === "function" && typeof Float32Array.of === "function" && typeof Float64Array.of === "function";
}
§%TypedArray%.prototype.subarray
?
function(){
return typeof Int8Array.prototype.subarray === "function" && typeof Uint8Array.prototype.subarray === "function" && typeof Uint8ClampedArray.prototype.subarray === "function" && typeof Int16Array.prototype.subarray === "function" && typeof Uint16Array.prototype.subarray === "function" && typeof Int32Array.prototype.subarray === "function" && typeof Uint32Array.prototype.subarray === "function" && typeof Float32Array.prototype.subarray === "function" && typeof Float64Array.prototype.subarray === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Int8Array.prototype.subarray === "function" && typeof Uint8Array.prototype.subarray === "function" && typeof Uint8ClampedArray.prototype.subarray === "function" && typeof Int16Array.prototype.subarray === "function" && typeof Uint16Array.prototype.subarray === "function" && typeof Int32Array.prototype.subarray === "function" && typeof Uint32Array.prototype.subarray === "function" && typeof Float32Array.prototype.subarray === "function" && typeof Float64Array.prototype.subarray === "function";
}
§%TypedArray%.prototype.join
?
function(){
return typeof Int8Array.prototype.join === "function" && typeof Uint8Array.prototype.join === "function" && typeof Uint8ClampedArray.prototype.join === "function" && typeof Int16Array.prototype.join === "function" && typeof Uint16Array.prototype.join === "function" && typeof Int32Array.prototype.join === "function" && typeof Uint32Array.prototype.join === "function" && typeof Float32Array.prototype.join === "function" && typeof Float64Array.prototype.join === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.join === "function" && typeof Uint8Array.prototype.join === "function" && typeof Uint8ClampedArray.prototype.join === "function" && typeof Int16Array.prototype.join === "function" && typeof Uint16Array.prototype.join === "function" && typeof Int32Array.prototype.join === "function" && typeof Uint32Array.prototype.join === "function" && typeof Float32Array.prototype.join === "function" && typeof Float64Array.prototype.join === "function";
}
§%TypedArray%.prototype.indexOf
?
function(){
return typeof Int8Array.prototype.indexOf === "function" && typeof Uint8Array.prototype.indexOf === "function" && typeof Uint8ClampedArray.prototype.indexOf === "function" && typeof Int16Array.prototype.indexOf === "function" && typeof Uint16Array.prototype.indexOf === "function" && typeof Int32Array.prototype.indexOf === "function" && typeof Uint32Array.prototype.indexOf === "function" && typeof Float32Array.prototype.indexOf === "function" && typeof Float64Array.prototype.indexOf === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.indexOf === "function" && typeof Uint8Array.prototype.indexOf === "function" && typeof Uint8ClampedArray.prototype.indexOf === "function" && typeof Int16Array.prototype.indexOf === "function" && typeof Uint16Array.prototype.indexOf === "function" && typeof Int32Array.prototype.indexOf === "function" && typeof Uint32Array.prototype.indexOf === "function" && typeof Float32Array.prototype.indexOf === "function" && typeof Float64Array.prototype.indexOf === "function";
}
§%TypedArray%.prototype.lastIndexOf
?
function(){
return typeof Int8Array.prototype.lastIndexOf === "function" && typeof Uint8Array.prototype.lastIndexOf === "function" && typeof Uint8ClampedArray.prototype.lastIndexOf === "function" && typeof Int16Array.prototype.lastIndexOf === "function" && typeof Uint16Array.prototype.lastIndexOf === "function" && typeof Int32Array.prototype.lastIndexOf === "function" && typeof Uint32Array.prototype.lastIndexOf === "function" && typeof Float32Array.prototype.lastIndexOf === "function" && typeof Float64Array.prototype.lastIndexOf === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.lastIndexOf === "function" && typeof Uint8Array.prototype.lastIndexOf === "function" && typeof Uint8ClampedArray.prototype.lastIndexOf === "function" && typeof Int16Array.prototype.lastIndexOf === "function" && typeof Uint16Array.prototype.lastIndexOf === "function" && typeof Int32Array.prototype.lastIndexOf === "function" && typeof Uint32Array.prototype.lastIndexOf === "function" && typeof Float32Array.prototype.lastIndexOf === "function" && typeof Float64Array.prototype.lastIndexOf === "function";
}
§%TypedArray%.prototype.slice
?
function(){
return typeof Int8Array.prototype.slice === "function" && typeof Uint8Array.prototype.slice === "function" && typeof Uint8ClampedArray.prototype.slice === "function" && typeof Int16Array.prototype.slice === "function" && typeof Uint16Array.prototype.slice === "function" && typeof Int32Array.prototype.slice === "function" && typeof Uint32Array.prototype.slice === "function" && typeof Float32Array.prototype.slice === "function" && typeof Float64Array.prototype.slice === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.slice === "function" && typeof Uint8Array.prototype.slice === "function" && typeof Uint8ClampedArray.prototype.slice === "function" && typeof Int16Array.prototype.slice === "function" && typeof Uint16Array.prototype.slice === "function" && typeof Int32Array.prototype.slice === "function" && typeof Uint32Array.prototype.slice === "function" && typeof Float32Array.prototype.slice === "function" && typeof Float64Array.prototype.slice === "function";
}
§%TypedArray%.prototype.every
?
function(){
return typeof Int8Array.prototype.every === "function" && typeof Uint8Array.prototype.every === "function" && typeof Uint8ClampedArray.prototype.every === "function" && typeof Int16Array.prototype.every === "function" && typeof Uint16Array.prototype.every === "function" && typeof Int32Array.prototype.every === "function" && typeof Uint32Array.prototype.every === "function" && typeof Float32Array.prototype.every === "function" && typeof Float64Array.prototype.every === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.every === "function" && typeof Uint8Array.prototype.every === "function" && typeof Uint8ClampedArray.prototype.every === "function" && typeof Int16Array.prototype.every === "function" && typeof Uint16Array.prototype.every === "function" && typeof Int32Array.prototype.every === "function" && typeof Uint32Array.prototype.every === "function" && typeof Float32Array.prototype.every === "function" && typeof Float64Array.prototype.every === "function";
}
§%TypedArray%.prototype.filter
?
function(){
return typeof Int8Array.prototype.filter === "function" && typeof Uint8Array.prototype.filter === "function" && typeof Uint8ClampedArray.prototype.filter === "function" && typeof Int16Array.prototype.filter === "function" && typeof Uint16Array.prototype.filter === "function" && typeof Int32Array.prototype.filter === "function" && typeof Uint32Array.prototype.filter === "function" && typeof Float32Array.prototype.filter === "function" && typeof Float64Array.prototype.filter === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.filter === "function" && typeof Uint8Array.prototype.filter === "function" && typeof Uint8ClampedArray.prototype.filter === "function" && typeof Int16Array.prototype.filter === "function" && typeof Uint16Array.prototype.filter === "function" && typeof Int32Array.prototype.filter === "function" && typeof Uint32Array.prototype.filter === "function" && typeof Float32Array.prototype.filter === "function" && typeof Float64Array.prototype.filter === "function";
}
§%TypedArray%.prototype.forEach
?
function(){
return typeof Int8Array.prototype.forEach === "function" && typeof Uint8Array.prototype.forEach === "function" && typeof Uint8ClampedArray.prototype.forEach === "function" && typeof Int16Array.prototype.forEach === "function" && typeof Uint16Array.prototype.forEach === "function" && typeof Int32Array.prototype.forEach === "function" && typeof Uint32Array.prototype.forEach === "function" && typeof Float32Array.prototype.forEach === "function" && typeof Float64Array.prototype.forEach === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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No
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No
function(){
return typeof Int8Array.prototype.forEach === "function" && typeof Uint8Array.prototype.forEach === "function" && typeof Uint8ClampedArray.prototype.forEach === "function" && typeof Int16Array.prototype.forEach === "function" && typeof Uint16Array.prototype.forEach === "function" && typeof Int32Array.prototype.forEach === "function" && typeof Uint32Array.prototype.forEach === "function" && typeof Float32Array.prototype.forEach === "function" && typeof Float64Array.prototype.forEach === "function";
}
§%TypedArray%.prototype.map
?
function(){
return typeof Int8Array.prototype.map === "function" && typeof Uint8Array.prototype.map === "function" && typeof Uint8ClampedArray.prototype.map === "function" && typeof Int16Array.prototype.map === "function" && typeof Uint16Array.prototype.map === "function" && typeof Int32Array.prototype.map === "function" && typeof Uint32Array.prototype.map === "function" && typeof Float32Array.prototype.map === "function" && typeof Float64Array.prototype.map === "function";
}
Yes
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Yes
No
No
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No
function(){
return typeof Int8Array.prototype.map === "function" && typeof Uint8Array.prototype.map === "function" && typeof Uint8ClampedArray.prototype.map === "function" && typeof Int16Array.prototype.map === "function" && typeof Uint16Array.prototype.map === "function" && typeof Int32Array.prototype.map === "function" && typeof Uint32Array.prototype.map === "function" && typeof Float32Array.prototype.map === "function" && typeof Float64Array.prototype.map === "function";
}
§%TypedArray%.prototype.reduce
?
function(){
return typeof Int8Array.prototype.reduce === "function" && typeof Uint8Array.prototype.reduce === "function" && typeof Uint8ClampedArray.prototype.reduce === "function" && typeof Int16Array.prototype.reduce === "function" && typeof Uint16Array.prototype.reduce === "function" && typeof Int32Array.prototype.reduce === "function" && typeof Uint32Array.prototype.reduce === "function" && typeof Float32Array.prototype.reduce === "function" && typeof Float64Array.prototype.reduce === "function";
}
Yes
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No
No
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No
function(){
return typeof Int8Array.prototype.reduce === "function" && typeof Uint8Array.prototype.reduce === "function" && typeof Uint8ClampedArray.prototype.reduce === "function" && typeof Int16Array.prototype.reduce === "function" && typeof Uint16Array.prototype.reduce === "function" && typeof Int32Array.prototype.reduce === "function" && typeof Uint32Array.prototype.reduce === "function" && typeof Float32Array.prototype.reduce === "function" && typeof Float64Array.prototype.reduce === "function";
}
§%TypedArray%.prototype.reduceRight
?
function(){
return typeof Int8Array.prototype.reduceRight === "function" && typeof Uint8Array.prototype.reduceRight === "function" && typeof Uint8ClampedArray.prototype.reduceRight === "function" && typeof Int16Array.prototype.reduceRight === "function" && typeof Uint16Array.prototype.reduceRight === "function" && typeof Int32Array.prototype.reduceRight === "function" && typeof Uint32Array.prototype.reduceRight === "function" && typeof Float32Array.prototype.reduceRight === "function" && typeof Float64Array.prototype.reduceRight === "function";
}
Yes
Yes
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Yes
No
No
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No
function(){
return typeof Int8Array.prototype.reduceRight === "function" && typeof Uint8Array.prototype.reduceRight === "function" && typeof Uint8ClampedArray.prototype.reduceRight === "function" && typeof Int16Array.prototype.reduceRight === "function" && typeof Uint16Array.prototype.reduceRight === "function" && typeof Int32Array.prototype.reduceRight === "function" && typeof Uint32Array.prototype.reduceRight === "function" && typeof Float32Array.prototype.reduceRight === "function" && typeof Float64Array.prototype.reduceRight === "function";
}
§%TypedArray%.prototype.reverse
?
function(){
return typeof Int8Array.prototype.reverse === "function" && typeof Uint8Array.prototype.reverse === "function" && typeof Uint8ClampedArray.prototype.reverse === "function" && typeof Int16Array.prototype.reverse === "function" && typeof Uint16Array.prototype.reverse === "function" && typeof Int32Array.prototype.reverse === "function" && typeof Uint32Array.prototype.reverse === "function" && typeof Float32Array.prototype.reverse === "function" && typeof Float64Array.prototype.reverse === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
No
No
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No
function(){
return typeof Int8Array.prototype.reverse === "function" && typeof Uint8Array.prototype.reverse === "function" && typeof Uint8ClampedArray.prototype.reverse === "function" && typeof Int16Array.prototype.reverse === "function" && typeof Uint16Array.prototype.reverse === "function" && typeof Int32Array.prototype.reverse === "function" && typeof Uint32Array.prototype.reverse === "function" && typeof Float32Array.prototype.reverse === "function" && typeof Float64Array.prototype.reverse === "function";
}
§%TypedArray%.prototype.some
?
function(){
return typeof Int8Array.prototype.some === "function" && typeof Uint8Array.prototype.some === "function" && typeof Uint8ClampedArray.prototype.some === "function" && typeof Int16Array.prototype.some === "function" && typeof Uint16Array.prototype.some === "function" && typeof Int32Array.prototype.some === "function" && typeof Uint32Array.prototype.some === "function" && typeof Float32Array.prototype.some === "function" && typeof Float64Array.prototype.some === "function";
}
Yes
Yes
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Yes
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Yes
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Yes
Yes
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Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.some === "function" && typeof Uint8Array.prototype.some === "function" && typeof Uint8ClampedArray.prototype.some === "function" && typeof Int16Array.prototype.some === "function" && typeof Uint16Array.prototype.some === "function" && typeof Int32Array.prototype.some === "function" && typeof Uint32Array.prototype.some === "function" && typeof Float32Array.prototype.some === "function" && typeof Float64Array.prototype.some === "function";
}
§%TypedArray%.prototype.sort
?
function(){
return typeof Int8Array.prototype.sort === "function" && typeof Uint8Array.prototype.sort === "function" && typeof Uint8ClampedArray.prototype.sort === "function" && typeof Int16Array.prototype.sort === "function" && typeof Uint16Array.prototype.sort === "function" && typeof Int32Array.prototype.sort === "function" && typeof Uint32Array.prototype.sort === "function" && typeof Float32Array.prototype.sort === "function" && typeof Float64Array.prototype.sort === "function";
}
Yes
Yes
Yes
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Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.sort === "function" && typeof Uint8Array.prototype.sort === "function" && typeof Uint8ClampedArray.prototype.sort === "function" && typeof Int16Array.prototype.sort === "function" && typeof Uint16Array.prototype.sort === "function" && typeof Int32Array.prototype.sort === "function" && typeof Uint32Array.prototype.sort === "function" && typeof Float32Array.prototype.sort === "function" && typeof Float64Array.prototype.sort === "function";
}
§%TypedArray%.prototype.copyWithin
?
function(){
return typeof Int8Array.prototype.copyWithin === "function" && typeof Uint8Array.prototype.copyWithin === "function" && typeof Uint8ClampedArray.prototype.copyWithin === "function" && typeof Int16Array.prototype.copyWithin === "function" && typeof Uint16Array.prototype.copyWithin === "function" && typeof Int32Array.prototype.copyWithin === "function" && typeof Uint32Array.prototype.copyWithin === "function" && typeof Float32Array.prototype.copyWithin === "function" && typeof Float64Array.prototype.copyWithin === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.copyWithin === "function" && typeof Uint8Array.prototype.copyWithin === "function" && typeof Uint8ClampedArray.prototype.copyWithin === "function" && typeof Int16Array.prototype.copyWithin === "function" && typeof Uint16Array.prototype.copyWithin === "function" && typeof Int32Array.prototype.copyWithin === "function" && typeof Uint32Array.prototype.copyWithin === "function" && typeof Float32Array.prototype.copyWithin === "function" && typeof Float64Array.prototype.copyWithin === "function";
}
§%TypedArray%.prototype.find
?
function(){
return typeof Int8Array.prototype.find === "function" && typeof Uint8Array.prototype.find === "function" && typeof Uint8ClampedArray.prototype.find === "function" && typeof Int16Array.prototype.find === "function" && typeof Uint16Array.prototype.find === "function" && typeof Int32Array.prototype.find === "function" && typeof Uint32Array.prototype.find === "function" && typeof Float32Array.prototype.find === "function" && typeof Float64Array.prototype.find === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.find === "function" && typeof Uint8Array.prototype.find === "function" && typeof Uint8ClampedArray.prototype.find === "function" && typeof Int16Array.prototype.find === "function" && typeof Uint16Array.prototype.find === "function" && typeof Int32Array.prototype.find === "function" && typeof Uint32Array.prototype.find === "function" && typeof Float32Array.prototype.find === "function" && typeof Float64Array.prototype.find === "function";
}
§%TypedArray%.prototype.findIndex
?
function(){
return typeof Int8Array.prototype.findIndex === "function" && typeof Uint8Array.prototype.findIndex === "function" && typeof Uint8ClampedArray.prototype.findIndex === "function" && typeof Int16Array.prototype.findIndex === "function" && typeof Uint16Array.prototype.findIndex === "function" && typeof Int32Array.prototype.findIndex === "function" && typeof Uint32Array.prototype.findIndex === "function" && typeof Float32Array.prototype.findIndex === "function" && typeof Float64Array.prototype.findIndex === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.findIndex === "function" && typeof Uint8Array.prototype.findIndex === "function" && typeof Uint8ClampedArray.prototype.findIndex === "function" && typeof Int16Array.prototype.findIndex === "function" && typeof Uint16Array.prototype.findIndex === "function" && typeof Int32Array.prototype.findIndex === "function" && typeof Uint32Array.prototype.findIndex === "function" && typeof Float32Array.prototype.findIndex === "function" && typeof Float64Array.prototype.findIndex === "function";
}
§%TypedArray%.prototype.fill
?
function(){
return typeof Int8Array.prototype.fill === "function" && typeof Uint8Array.prototype.fill === "function" && typeof Uint8ClampedArray.prototype.fill === "function" && typeof Int16Array.prototype.fill === "function" && typeof Uint16Array.prototype.fill === "function" && typeof Int32Array.prototype.fill === "function" && typeof Uint32Array.prototype.fill === "function" && typeof Float32Array.prototype.fill === "function" && typeof Float64Array.prototype.fill === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof Int8Array.prototype.fill === "function" && typeof Uint8Array.prototype.fill === "function" && typeof Uint8ClampedArray.prototype.fill === "function" && typeof Int16Array.prototype.fill === "function" && typeof Uint16Array.prototype.fill === "function" && typeof Int32Array.prototype.fill === "function" && typeof Uint32Array.prototype.fill === "function" && typeof Float32Array.prototype.fill === "function" && typeof Float64Array.prototype.fill === "function";
}
§%TypedArray%.prototype.keys
?
function(){
return typeof Int8Array.prototype.keys === "function" && typeof Uint8Array.prototype.keys === "function" && typeof Uint8ClampedArray.prototype.keys === "function" && typeof Int16Array.prototype.keys === "function" && typeof Uint16Array.prototype.keys === "function" && typeof Int32Array.prototype.keys === "function" && typeof Uint32Array.prototype.keys === "function" && typeof Float32Array.prototype.keys === "function" && typeof Float64Array.prototype.keys === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Int8Array.prototype.keys === "function" && typeof Uint8Array.prototype.keys === "function" && typeof Uint8ClampedArray.prototype.keys === "function" && typeof Int16Array.prototype.keys === "function" && typeof Uint16Array.prototype.keys === "function" && typeof Int32Array.prototype.keys === "function" && typeof Uint32Array.prototype.keys === "function" && typeof Float32Array.prototype.keys === "function" && typeof Float64Array.prototype.keys === "function";
}
§%TypedArray%.prototype.values
?
function(){
return typeof Int8Array.prototype.values === "function" && typeof Uint8Array.prototype.values === "function" && typeof Uint8ClampedArray.prototype.values === "function" && typeof Int16Array.prototype.values === "function" && typeof Uint16Array.prototype.values === "function" && typeof Int32Array.prototype.values === "function" && typeof Uint32Array.prototype.values === "function" && typeof Float32Array.prototype.values === "function" && typeof Float64Array.prototype.values === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
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Yes
Yes
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Yes
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Yes
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Yes
Yes
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Yes
Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Int8Array.prototype.values === "function" && typeof Uint8Array.prototype.values === "function" && typeof Uint8ClampedArray.prototype.values === "function" && typeof Int16Array.prototype.values === "function" && typeof Uint16Array.prototype.values === "function" && typeof Int32Array.prototype.values === "function" && typeof Uint32Array.prototype.values === "function" && typeof Float32Array.prototype.values === "function" && typeof Float64Array.prototype.values === "function";
}
§%TypedArray%.prototype.entries
?
function(){
return typeof Int8Array.prototype.entries === "function" && typeof Uint8Array.prototype.entries === "function" && typeof Uint8ClampedArray.prototype.entries === "function" && typeof Int16Array.prototype.entries === "function" && typeof Uint16Array.prototype.entries === "function" && typeof Int32Array.prototype.entries === "function" && typeof Uint32Array.prototype.entries === "function" && typeof Float32Array.prototype.entries === "function" && typeof Float64Array.prototype.entries === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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No
No
function(){
return typeof Int8Array.prototype.entries === "function" && typeof Uint8Array.prototype.entries === "function" && typeof Uint8ClampedArray.prototype.entries === "function" && typeof Int16Array.prototype.entries === "function" && typeof Uint16Array.prototype.entries === "function" && typeof Int32Array.prototype.entries === "function" && typeof Uint32Array.prototype.entries === "function" && typeof Float32Array.prototype.entries === "function" && typeof Float64Array.prototype.entries === "function";
}
§%TypedArray%.prototype[Symbol.iterator]
?
function(){
return typeof Int8Array.prototype[Symbol.iterator] === "function" && typeof Uint8Array.prototype[Symbol.iterator] === "function" && typeof Uint8ClampedArray.prototype[Symbol.iterator] === "function" && typeof Int16Array.prototype[Symbol.iterator] === "function" && typeof Uint16Array.prototype[Symbol.iterator] === "function" && typeof Int32Array.prototype[Symbol.iterator] === "function" && typeof Uint32Array.prototype[Symbol.iterator] === "function" && typeof Float32Array.prototype[Symbol.iterator] === "function" && typeof Float64Array.prototype[Symbol.iterator] === "function";
}
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Error
Error
function(){
return typeof Int8Array.prototype[Symbol.iterator] === "function" && typeof Uint8Array.prototype[Symbol.iterator] === "function" && typeof Uint8ClampedArray.prototype[Symbol.iterator] === "function" && typeof Int16Array.prototype[Symbol.iterator] === "function" && typeof Uint16Array.prototype[Symbol.iterator] === "function" && typeof Int32Array.prototype[Symbol.iterator] === "function" && typeof Uint32Array.prototype[Symbol.iterator] === "function" && typeof Float32Array.prototype[Symbol.iterator] === "function" && typeof Float64Array.prototype[Symbol.iterator] === "function";
}
§%TypedArray%[Symbol.species]
?
function(){
return typeof Int8Array[Symbol.species] === "function" && typeof Uint8Array[Symbol.species] === "function" && typeof Uint8ClampedArray[Symbol.species] === "function" && typeof Int16Array[Symbol.species] === "function" && typeof Uint16Array[Symbol.species] === "function" && typeof Int32Array[Symbol.species] === "function" && typeof Uint32Array[Symbol.species] === "function" && typeof Float32Array[Symbol.species] === "function" && typeof Float64Array[Symbol.species] === "function";
}
Yes
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No
Flag
No
No
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No
No
Error
Error
function(){
return typeof Int8Array[Symbol.species] === "function" && typeof Uint8Array[Symbol.species] === "function" && typeof Uint8ClampedArray[Symbol.species] === "function" && typeof Int16Array[Symbol.species] === "function" && typeof Uint16Array[Symbol.species] === "function" && typeof Int32Array[Symbol.species] === "function" && typeof Uint32Array[Symbol.species] === "function" && typeof Float32Array[Symbol.species] === "function" && typeof Float64Array[Symbol.species] === "function";
}

Map

§basic functionality
?
function(){
var key = {}; var map = new Map(); map.set(key, 123); return map.has(key) && map.get(key) === 123;
}
Yes
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Error
Flag
function(){
var key = {}; var map = new Map(); map.set(key, 123); return map.has(key) && map.get(key) === 123;
}
§constructor arguments
?
function(){
var key1 = {}; var key2 = {}; var map = new Map([[key1, 123], [key2, 456]]); return map.has(key1) && map.get(key1) === 123 && map.has(key2) && map.get(key2) === 456;
}
Yes
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Yes
Error
No
function(){
var key1 = {}; var key2 = {}; var map = new Map([[key1, 123], [key2, 456]]); return map.has(key1) && map.get(key1) === 123 && map.has(key2) && map.get(key2) === 456;
}
§constructor requires new
?
function(){
new Map(); try { Map(); return false; } catch(e) { return true; }
}
Yes
Yes
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Error
No
function(){
new Map(); try { Map(); return false; } catch(e) { return true; }
}
§constructor accepts null
?
function(){
new Map(null); return true;
}
Yes
Yes
Yes
Yes
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Error
Flag
function(){
new Map(null); return true;
}
§constructor invokes set
?
function(){
var passed = false; var _set = Map.prototype.set; Map.prototype.set = function(k, v) { passed = true; }; new Map([ [1, 2] ]); Map.prototype.set = _set; return passed;
}
Yes
Yes
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Error
No
function(){
var passed = false; var _set = Map.prototype.set; Map.prototype.set = function(k, v) { passed = true; }; new Map([ [1, 2] ]); Map.prototype.set = _set; return passed;
}
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { new Map(iter); } catch(e){} return closed;
}
Yes
Yes
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No
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No
No
No
No
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { new Map(iter); } catch(e){} return closed;
}
§Map.prototype.set returns this
?
function(){
var map = new Map(); return map.set(0, 0) === map;
}
Yes
Yes
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Yes
Error
No
function(){
var map = new Map(); return map.set(0, 0) === map;
}
§-0 key converts to +0
?
function(){
var map = new Map(); map.set(-0, "foo"); var k; map.forEach(function (value, key) { k = 1 / key; }); return k === Infinity && map.get(+0) === "foo";
}
Yes
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No
No
Error
Error
function(){
var map = new Map(); map.set(-0, "foo"); var k; map.forEach(function (value, key) { k = 1 / key; }); return k === Infinity && map.get(+0) === "foo";
}
§Map.prototype.size
?
function(){
var key = {}; var map = new Map(); map.set(key, 123); return map.size === 1;
}
Yes
Yes
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Error
No
function(){
var key = {}; var map = new Map(); map.set(key, 123); return map.size === 1;
}
§Map.prototype.delete
?
function(){
return typeof Map.prototype.delete === "function";
}
Yes
Yes
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Error
Flag
function(){
return typeof Map.prototype.delete === "function";
}
§Map.prototype.clear
?
function(){
return typeof Map.prototype.clear === "function";
}
Yes
Yes
Yes
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Error
No
function(){
return typeof Map.prototype.clear === "function";
}
§Map.prototype.forEach
?
function(){
return typeof Map.prototype.forEach === "function";
}
Yes
Yes
Yes
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Error
No
function(){
return typeof Map.prototype.forEach === "function";
}
§Map.prototype.keys
?
function(){
return typeof Map.prototype.keys === "function";
}
Yes
Yes
Yes
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Error
No
function(){
return typeof Map.prototype.keys === "function";
}
§Map.prototype.values
?
function(){
return typeof Map.prototype.values === "function";
}
Yes
Yes
Yes
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Error
No
function(){
return typeof Map.prototype.values === "function";
}
§Map.prototype.entries
?
function(){
return typeof Map.prototype.entries === "function";
}
Yes
Yes
Yes
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Error
No
function(){
return typeof Map.prototype.entries === "function";
}
§Map.prototype[Symbol.iterator]
?
function(){
return typeof Map.prototype[Symbol.iterator] === "function";
}
Yes
Yes
Yes
Yes
Yes
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Error
Error
function(){
return typeof Map.prototype[Symbol.iterator] === "function";
}
§Map.prototype isn't an instance
?
function(){
new Map(); var obj = {}; try { Map.prototype.has(obj); } catch(e) { return true; }
}
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Error
Flag
function(){
new Map(); var obj = {}; try { Map.prototype.has(obj); } catch(e) { return true; }
}
§Map iterator prototype chain
?
function(){
// Iterator instance var iterator = new Map()[Symbol.iterator](); // %MapIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
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Error
Error
function(){
// Iterator instance var iterator = new Map()[Symbol.iterator](); // %MapIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
§Map[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(Map, Symbol.species); return 'get' in prop && Map[Symbol.species] === Map;
}
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Error
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Error
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Error
Error
Error
Error
Error
Error
function(){
var prop = Object.getOwnPropertyDescriptor(Map, Symbol.species); return 'get' in prop && Map[Symbol.species] === Map;
}

Set

§basic functionality
?
function(){
var obj = {}; var set = new Set(); set.add(123); set.add(123); return set.has(123);
}
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Error
Flag
function(){
var obj = {}; var set = new Set(); set.add(123); set.add(123); return set.has(123);
}
§constructor arguments
?
function(){
var obj1 = {}; var obj2 = {}; var set = new Set([obj1, obj2]); return set.has(obj1) && set.has(obj2);
}
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Error
No
function(){
var obj1 = {}; var obj2 = {}; var set = new Set([obj1, obj2]); return set.has(obj1) && set.has(obj2);
}
§constructor requires new
?
function(){
new Set(); try { Set(); return false; } catch(e) { return true; }
}
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Error
No
function(){
new Set(); try { Set(); return false; } catch(e) { return true; }
}
§constructor accepts null
?
function(){
new Set(null); return true;
}
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Error
Flag
function(){
new Set(null); return true;
}
§constructor invokes add
?
function(){
var passed = false; var _add = Set.prototype.add; Set.prototype.add = function(v) { passed = true; }; new Set([1]); Set.prototype.add = _add; return passed;
}
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Error
No
function(){
var passed = false; var _add = Set.prototype.add; Set.prototype.add = function(v) { passed = true; }; new Set([1]); Set.prototype.add = _add; return passed;
}
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); var add = Set.prototype.add; Set.prototype.add = function(){ throw 0 }; try { new Set(iter); } catch(e){} Set.prototype.add = add; return closed;
}
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Error
No
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); var add = Set.prototype.add; Set.prototype.add = function(){ throw 0 }; try { new Set(iter); } catch(e){} Set.prototype.add = add; return closed;
}
§Set.prototype.add returns this
?
function(){
var set = new Set(); return set.add(0) === set;
}
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Error
No
function(){
var set = new Set(); return set.add(0) === set;
}
§-0 key converts to +0
?
function(){
var set = new Set(); set.add(-0); var k; set.forEach(function (value) { k = 1 / value; }); return k === Infinity && set.has(+0);
}
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No
No
Error
Error
function(){
var set = new Set(); set.add(-0); var k; set.forEach(function (value) { k = 1 / value; }); return k === Infinity && set.has(+0);
}
§Set.prototype.size
?
function(){
var obj = {}; var set = new Set(); set.add(123); set.add(123); set.add(456); return set.size === 2;
}
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Error
No
function(){
var obj = {}; var set = new Set(); set.add(123); set.add(123); set.add(456); return set.size === 2;
}
§Set.prototype.delete
?
function(){
return typeof Set.prototype.delete === "function";
}
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Error
Flag
function(){
return typeof Set.prototype.delete === "function";
}
§Set.prototype.clear
?
function(){
return typeof Set.prototype.clear === "function";
}
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Error
No
function(){
return typeof Set.prototype.clear === "function";
}
§Set.prototype.forEach
?
function(){
return typeof Set.prototype.forEach === "function";
}
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Error
No
function(){
return typeof Set.prototype.forEach === "function";
}
§Set.prototype.keys
?
function(){
return typeof Set.prototype.keys === "function";
}
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Error
No
function(){
return typeof Set.prototype.keys === "function";
}
§Set.prototype.values
?
function(){
return typeof Set.prototype.values === "function";
}
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Error
No
function(){
return typeof Set.prototype.values === "function";
}
§Set.prototype.entries
?
function(){
return typeof Set.prototype.entries === "function";
}
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Error
No
function(){
return typeof Set.prototype.entries === "function";
}
§Set.prototype[Symbol.iterator]
?
function(){
return typeof Set.prototype[Symbol.iterator] === "function";
}
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Error
Error
function(){
return typeof Set.prototype[Symbol.iterator] === "function";
}
§Set.prototype isn't an instance
?
function(){
new Set(); var obj = {}; try { Set.prototype.has(obj); } catch(e) { return true; }
}
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Error
Flag
function(){
new Set(); var obj = {}; try { Set.prototype.has(obj); } catch(e) { return true; }
}
§Set iterator prototype chain
?
function(){
// Iterator instance var iterator = new Set()[Symbol.iterator](); // %SetIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
Yes
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No
No
Error
Error
function(){
// Iterator instance var iterator = new Set()[Symbol.iterator](); // %SetIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
§Set[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(Set, Symbol.species); return 'get' in prop && Set[Symbol.species] === Set;
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var prop = Object.getOwnPropertyDescriptor(Set, Symbol.species); return 'get' in prop && Set[Symbol.species] === Set;
}

WeakMap

§basic functionality
?
function(){
var key = {}; var weakmap = new WeakMap(); weakmap.set(key, 123); return weakmap.has(key) && weakmap.get(key) === 123;
}
Yes
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Error
Flag
function(){
var key = {}; var weakmap = new WeakMap(); weakmap.set(key, 123); return weakmap.has(key) && weakmap.get(key) === 123;
}
§constructor arguments
?
function(){
var key1 = {}; var key2 = {}; var weakmap = new WeakMap([[key1, 123], [key2, 456]]); return weakmap.has(key1) && weakmap.get(key1) === 123 && weakmap.has(key2) && weakmap.get(key2) === 456;
}
Yes
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Error
No
function(){
var key1 = {}; var key2 = {}; var weakmap = new WeakMap([[key1, 123], [key2, 456]]); return weakmap.has(key1) && weakmap.get(key1) === 123 && weakmap.has(key2) && weakmap.get(key2) === 456;
}
§constructor requires new
?
function(){
new WeakMap(); try { WeakMap(); return false; } catch(e) { return true; }
}
Yes
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Yes
Error
No
function(){
new WeakMap(); try { WeakMap(); return false; } catch(e) { return true; }
}
§constructor accepts null
?
function(){
new WeakMap(null); return true;
}
Yes
Yes
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Error
Flag
function(){
new WeakMap(null); return true;
}
§constructor invokes set
?
function(){
var passed = false; var _set = WeakMap.prototype.set; WeakMap.prototype.set = function(k, v) { passed = true; }; new WeakMap([ [{ }, 42] ]); WeakMap.prototype.set = _set; return passed;
}
Yes
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Error
No
function(){
var passed = false; var _set = WeakMap.prototype.set; WeakMap.prototype.set = function(k, v) { passed = true; }; new WeakMap([ [{ }, 42] ]); WeakMap.prototype.set = _set; return passed;
}
§frozen objects as keys
?
function(){
var f = Object.freeze({}); var m = new WeakMap; m.set(f, 42); return m.get(f) === 42;
}
Yes
Yes
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Error
Flag
function(){
var f = Object.freeze({}); var m = new WeakMap; m.set(f, 42); return m.get(f) === 42;
}
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { new WeakMap(iter); } catch(e){} return closed;
}
Yes
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No
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No
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { new WeakMap(iter); } catch(e){} return closed;
}
§WeakMap.prototype.set returns this
?
function(){
var weakmap = new WeakMap(); var key = {}; return weakmap.set(key, 0) === weakmap;
}
Yes
Yes
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Error
No
function(){
var weakmap = new WeakMap(); var key = {}; return weakmap.set(key, 0) === weakmap;
}
§WeakMap.prototype.delete
?
function(){
return typeof WeakMap.prototype.delete === "function";
}
Yes
Yes
Yes
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Error
Flag
function(){
return typeof WeakMap.prototype.delete === "function";
}
§no WeakMap.prototype.clear method
?
function(){
if (!("clear" in WeakMap.prototype)) { return true; } var m = new WeakMap(); var key = {}; m.set(key, 2); m.clear(); return m.has(key);
}
Yes
Yes
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No
No
Error
Flag
function(){
if (!("clear" in WeakMap.prototype)) { return true; } var m = new WeakMap(); var key = {}; m.set(key, 2); m.clear(); return m.has(key);
}
§.has, .get and .delete methods accept primitives
?
function(){
var m = new WeakMap; return m.has(1) === false && m.get(1) === void undefined && m.delete(1) === false;
}
Yes
Yes
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Error
Error
Error
Error
function(){
var m = new WeakMap; return m.has(1) === false && m.get(1) === void undefined && m.delete(1) === false;
}
§WeakMap.prototype isn't an instance
?
function(){
new WeakMap(); var obj = {}; try { WeakMap.prototype.has(obj); } catch(e) { return true; }
}
Yes
Yes
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Yes
Error
Flag
function(){
new WeakMap(); var obj = {}; try { WeakMap.prototype.has(obj); } catch(e) { return true; }
}

WeakSet

§basic functionality
?
function(){
var obj1 = {}; var weakset = new WeakSet(); weakset.add(obj1); weakset.add(obj1); return weakset.has(obj1);
}
Yes
Yes
Yes
Yes
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Yes
Error
Error
function(){
var obj1 = {}; var weakset = new WeakSet(); weakset.add(obj1); weakset.add(obj1); return weakset.has(obj1);
}
§constructor arguments
?
function(){
var obj1 = {}, obj2 = {}; var weakset = new WeakSet([obj1, obj2]); return weakset.has(obj1) && weakset.has(obj2);
}
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Error
Error
function(){
var obj1 = {}, obj2 = {}; var weakset = new WeakSet([obj1, obj2]); return weakset.has(obj1) && weakset.has(obj2);
}
§constructor requires new
?
function(){
new WeakSet(); try { WeakSet(); return false; } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Error
Error
function(){
new WeakSet(); try { WeakSet(); return false; } catch(e) { return true; }
}
§constructor accepts null
?
function(){
new WeakSet(null); return true;
}
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
new WeakSet(null); return true;
}
§constructor invokes add
?
function(){
var passed = false; var _add = WeakSet.prototype.add; WeakSet.prototype.add = function(v) { passed = true; }; new WeakSet([ { } ]); WeakSet.prototype.add = _add; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var passed = false; var _add = WeakSet.prototype.add; WeakSet.prototype.add = function(v) { passed = true; }; new WeakSet([ { } ]); WeakSet.prototype.add = _add; return passed;
}
§iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { new WeakSet(iter); } catch(e){} return closed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
No
No
No
No
No
No
No
No
No
No
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { new WeakSet(iter); } catch(e){} return closed;
}
§WeakSet.prototype.add returns this
?
function(){
var weakset = new WeakSet(); var obj = {}; return weakset.add(obj) === weakset;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var weakset = new WeakSet(); var obj = {}; return weakset.add(obj) === weakset;
}
§WeakSet.prototype.delete
?
function(){
return typeof WeakSet.prototype.delete === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
return typeof WeakSet.prototype.delete === "function";
}
§no WeakSet.prototype.clear method
?
function(){
if (!("clear" in WeakSet.prototype)) { return true; } var s = new WeakSet(); var key = {}; s.add(key); s.clear(); return s.has(key);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
No
No
Error
Error
function(){
if (!("clear" in WeakSet.prototype)) { return true; } var s = new WeakSet(); var key = {}; s.add(key); s.clear(); return s.has(key);
}
§.has and .delete methods accept primitives
?
function(){
var s = new WeakSet; return s.has(1) === false && s.delete(1) === false;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var s = new WeakSet; return s.has(1) === false && s.delete(1) === false;
}
§WeakSet.prototype isn't an instance
?
function(){
new WeakSet(); var obj = {}; try { WeakSet.prototype.has(obj); } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
new WeakSet(); var obj = {}; try { WeakSet.prototype.has(obj); } catch(e) { return true; }
}

Proxy

§constructor requires new
?
function(){
new Proxy({}, {}); try { Proxy({}, {}); return false; } catch(e) { return true; }
}
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
new Proxy({}, {}); try { Proxy({}, {}); return false; } catch(e) { return true; }
}
§no "prototype" property
?
function(){
new Proxy({}, {}); return !Proxy.hasOwnProperty('prototype');
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
new Proxy({}, {}); return !Proxy.hasOwnProperty('prototype');
}
§"get" handler
?
function(){
var proxied = { }; var proxy = new Proxy(proxied, { get: function (t, k, r) { return t === proxied && k === "foo" && r === proxy && 5; } }); return proxy.foo === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var proxied = { }; var proxy = new Proxy(proxied, { get: function (t, k, r) { return t === proxied && k === "foo" && r === proxy && 5; } }); return proxy.foo === 5;
}
§"get" handler, instances of proxies
?
function(){
var proxied = { }; var proxy = Object.create(new Proxy(proxied, { get: function (t, k, r) { return t === proxied && k === "foo" && r === proxy && 5; } })); return proxy.foo === 5;
}
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var proxied = { }; var proxy = Object.create(new Proxy(proxied, { get: function (t, k, r) { return t === proxied && k === "foo" && r === proxy && 5; } })); return proxy.foo === 5;
}
§"get" handler invariants
?
function(){
var passed = false; var proxied = { }; var proxy = new Proxy(proxied, { get: function () { passed = true; return 4; } }); // The value reported for a property must be the same as the value of the corresponding // target object property if the target object property is a non-writable, // non-configurable own data property. Object.defineProperty(proxied, "foo", { value: 5, enumerable: true }); try { proxy.foo; return false; } catch(e) {} // The value reported for a property must be undefined if the corresponding target // object property is a non-configurable own accessor property that has undefined // as its [[Get]] attribute. Object.defineProperty(proxied, "bar", { set: function(){}, enumerable: true }); try { proxy.bar; return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var passed = false; var proxied = { }; var proxy = new Proxy(proxied, { get: function () { passed = true; return 4; } }); // The value reported for a property must be the same as the value of the corresponding // target object property if the target object property is a non-writable, // non-configurable own data property. Object.defineProperty(proxied, "foo", { value: 5, enumerable: true }); try { proxy.foo; return false; } catch(e) {} // The value reported for a property must be undefined if the corresponding target // object property is a non-configurable own accessor property that has undefined // as its [[Get]] attribute. Object.defineProperty(proxied, "bar", { set: function(){}, enumerable: true }); try { proxy.bar; return false; } catch(e) {} return passed;
}
§"set" handler
?
function(){
var proxied = { }; var passed = false; var proxy = new Proxy(proxied, { set: function (t, k, v, r) { passed = t === proxied && k + v === "foobar" && r === proxy; } }); proxy.foo = "bar"; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var proxied = { }; var passed = false; var proxy = new Proxy(proxied, { set: function (t, k, v, r) { passed = t === proxied && k + v === "foobar" && r === proxy; } }); proxy.foo = "bar"; return passed;
}
§"set" handler, instances of proxies
?
function(){
var proxied = { }; var passed = false; var proxy = Object.create(new Proxy(proxied, { set: function (t, k, v, r) { passed = t === proxied && k + v === "foobar" && r === proxy; } })); proxy.foo = "bar"; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var proxied = { }; var passed = false; var proxy = Object.create(new Proxy(proxied, { set: function (t, k, v, r) { passed = t === proxied && k + v === "foobar" && r === proxy; } })); proxy.foo = "bar"; return passed;
}
§"set" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // Cannot change the value of a property to be different from the value of // the corresponding target object if the corresponding target object // property is a non-writable, non-configurable own data property. var proxied = {}; var proxy = new Proxy(proxied, { set: function () { passed = true; return true; } }); Object.defineProperty(proxied, "foo", { value: 2, enumerable: true }); proxy.foo = 2; try { proxy.foo = 4; return false; } catch(e) {} // Cannot set the value of a property if the corresponding target // object property is a non-configurable own accessor property // that has undefined as its [[Set]] attribute. Object.defineProperty(proxied, "bar", { get: function(){}, enumerable: true }); try { proxy.bar = 2; return false; } catch(e) {} return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var passed = false; new Proxy({},{}); // Cannot change the value of a property to be different from the value of // the corresponding target object if the corresponding target object // property is a non-writable, non-configurable own data property. var proxied = {}; var proxy = new Proxy(proxied, { set: function () { passed = true; return true; } }); Object.defineProperty(proxied, "foo", { value: 2, enumerable: true }); proxy.foo = 2; try { proxy.foo = 4; return false; } catch(e) {} // Cannot set the value of a property if the corresponding target // object property is a non-configurable own accessor property // that has undefined as its [[Set]] attribute. Object.defineProperty(proxied, "bar", { get: function(){}, enumerable: true }); try { proxy.bar = 2; return false; } catch(e) {} return passed;
}
§"has" handler
?
function(){
var proxied = {}; var passed = false; "foo" in new Proxy(proxied, { has: function (t, k) { passed = t === proxied && k === "foo"; } }); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var proxied = {}; var passed = false; "foo" in new Proxy(proxied, { has: function (t, k) { passed = t === proxied && k === "foo"; } }); return passed;
}
§"has" handler, instances of proxies
?
function(){
var proxied = {}; var passed = false; "foo" in Object.create(new Proxy(proxied, { has: function (t, k) { passed = t === proxied && k === "foo"; } })); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Error
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function(){
var proxied = {}; var passed = false; "foo" in Object.create(new Proxy(proxied, { has: function (t, k) { passed = t === proxied && k === "foo"; } })); return passed;
}
§"has" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // A property cannot be reported as non-existent, if it exists as a // non-configurable own property of the target object. var proxied = {}; var proxy = new Proxy(proxied, { has: function () { passed = true; return false; } }); Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { 'foo' in proxy; return false; } catch(e) {} // A property cannot be reported as non-existent, if it exists as an // own property of the target object and the target object is not extensible. proxied.bar = 2; Object.preventExtensions(proxied); try { 'bar' in proxy; return false; } catch(e) {} return passed;
}
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Error
Error
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function(){
var passed = false; new Proxy({},{}); // A property cannot be reported as non-existent, if it exists as a // non-configurable own property of the target object. var proxied = {}; var proxy = new Proxy(proxied, { has: function () { passed = true; return false; } }); Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { 'foo' in proxy; return false; } catch(e) {} // A property cannot be reported as non-existent, if it exists as an // own property of the target object and the target object is not extensible. proxied.bar = 2; Object.preventExtensions(proxied); try { 'bar' in proxy; return false; } catch(e) {} return passed;
}
§"deleteProperty" handler
?
function(){
var proxied = {}; var passed = false; delete new Proxy(proxied, { deleteProperty: function (t, k) { passed = t === proxied && k === "foo"; } }).foo; return passed;
}
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Error
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Error
function(){
var proxied = {}; var passed = false; delete new Proxy(proxied, { deleteProperty: function (t, k) { passed = t === proxied && k === "foo"; } }).foo; return passed;
}
§"deleteProperty" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // A property cannot be reported as deleted, if it exists as a non-configurable // own property of the target object. var proxied = {}; Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { delete new Proxy(proxied, { deleteProperty: function () { passed = true; return true; } }).foo; return false; } catch(e) {} return passed;
}
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Error
Error
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Error
function(){
var passed = false; new Proxy({},{}); // A property cannot be reported as deleted, if it exists as a non-configurable // own property of the target object. var proxied = {}; Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { delete new Proxy(proxied, { deleteProperty: function () { passed = true; return true; } }).foo; return false; } catch(e) {} return passed;
}
§"getOwnPropertyDescriptor" handler
?
function(){
var proxied = {}; var fakeDesc = { value: "foo", configurable: true }; var returnedDesc = Object.getOwnPropertyDescriptor( new Proxy(proxied, { getOwnPropertyDescriptor: function (t, k) { return t === proxied && k === "foo" && fakeDesc; } }), "foo" ); return (returnedDesc.value === fakeDesc.value && returnedDesc.configurable === fakeDesc.configurable && returnedDesc.writable === false && returnedDesc.enumerable === false);
}
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Error
Error
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Error
function(){
var proxied = {}; var fakeDesc = { value: "foo", configurable: true }; var returnedDesc = Object.getOwnPropertyDescriptor( new Proxy(proxied, { getOwnPropertyDescriptor: function (t, k) { return t === proxied && k === "foo" && fakeDesc; } }), "foo" ); return (returnedDesc.value === fakeDesc.value && returnedDesc.configurable === fakeDesc.configurable && returnedDesc.writable === false && returnedDesc.enumerable === false);
}
§"getOwnPropertyDescriptor" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // A property cannot be reported as non-existent, if it exists as a non-configurable // own property of the target object. var proxied = {}; var proxy = new Proxy(proxied, { getOwnPropertyDescriptor: function () { passed = true; return undefined; } }); Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { Object.getOwnPropertyDescriptor(proxy, "foo"); return false; } catch(e) {} // A property cannot be reported as non-existent, if it exists as an own property // of the target object and the target object is not extensible. proxied.bar = 3; Object.preventExtensions(proxied); try { Object.getOwnPropertyDescriptor(proxy, "bar"); return false; } catch(e) {} // A property cannot be reported as existent, if it does not exists as an own property // of the target object and the target object is not extensible. try { Object.getOwnPropertyDescriptor(new Proxy(proxied, { getOwnPropertyDescriptor: function() { return { value: 2, configurable: true, writable: true, enumerable: true }; }}), "baz"); return false; } catch(e) {} // A property cannot be reported as non-configurable, if it does not exists as an own // property of the target object or if it exists as a configurable own property of // the target object. try { Object.getOwnPropertyDescriptor(new Proxy({}, { getOwnPropertyDescriptor: function() { return { value: 2, configurable: false, writable: true, enumerable: true }; }}), "baz"); return false; } catch(e) {} try { Object.getOwnPropertyDescriptor(new Proxy({baz:1}, { getOwnPropertyDescriptor: function() { return { value: 1, configurable: false, writable: true, enumerable: true }; }}), "baz"); return false; } catch(e) {} return passed;
}
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Error
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Error
function(){
var passed = false; new Proxy({},{}); // A property cannot be reported as non-existent, if it exists as a non-configurable // own property of the target object. var proxied = {}; var proxy = new Proxy(proxied, { getOwnPropertyDescriptor: function () { passed = true; return undefined; } }); Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { Object.getOwnPropertyDescriptor(proxy, "foo"); return false; } catch(e) {} // A property cannot be reported as non-existent, if it exists as an own property // of the target object and the target object is not extensible. proxied.bar = 3; Object.preventExtensions(proxied); try { Object.getOwnPropertyDescriptor(proxy, "bar"); return false; } catch(e) {} // A property cannot be reported as existent, if it does not exists as an own property // of the target object and the target object is not extensible. try { Object.getOwnPropertyDescriptor(new Proxy(proxied, { getOwnPropertyDescriptor: function() { return { value: 2, configurable: true, writable: true, enumerable: true }; }}), "baz"); return false; } catch(e) {} // A property cannot be reported as non-configurable, if it does not exists as an own // property of the target object or if it exists as a configurable own property of // the target object. try { Object.getOwnPropertyDescriptor(new Proxy({}, { getOwnPropertyDescriptor: function() { return { value: 2, configurable: false, writable: true, enumerable: true }; }}), "baz"); return false; } catch(e) {} try { Object.getOwnPropertyDescriptor(new Proxy({baz:1}, { getOwnPropertyDescriptor: function() { return { value: 1, configurable: false, writable: true, enumerable: true }; }}), "baz"); return false; } catch(e) {} return passed;
}
§"defineProperty" handler
?
function(){
var proxied = {}; var passed = false; Object.defineProperty( new Proxy(proxied, { defineProperty: function (t, k, d) { passed = t === proxied && k === "foo" && d.value === 5; return true; } }), "foo", { value: 5, configurable: true } ); return passed;
}
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Error
Error
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Error
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Error
function(){
var proxied = {}; var passed = false; Object.defineProperty( new Proxy(proxied, { defineProperty: function (t, k, d) { passed = t === proxied && k === "foo" && d.value === 5; return true; } }), "foo", { value: 5, configurable: true } ); return passed;
}
§"defineProperty" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // A property cannot be added, if the target object is not extensible. var proxied = Object.preventExtensions({}); var proxy = new Proxy(proxied, { defineProperty: function() { passed = true; return true; } }); try { Object.defineProperty(proxy, "foo", { value: 2 }); return false; } catch(e) {} // A property cannot be non-configurable, unless there exists a corresponding // non-configurable own property of the target object. try { Object.defineProperty( new Proxy({ bar: true }, { defineProperty: function () { return true; } }), "bar", { value: 5, configurable: false, writable: true, enumerable: true } ); return false; } catch(e) {} return passed;
}
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Error
Error
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function(){
var passed = false; new Proxy({},{}); // A property cannot be added, if the target object is not extensible. var proxied = Object.preventExtensions({}); var proxy = new Proxy(proxied, { defineProperty: function() { passed = true; return true; } }); try { Object.defineProperty(proxy, "foo", { value: 2 }); return false; } catch(e) {} // A property cannot be non-configurable, unless there exists a corresponding // non-configurable own property of the target object. try { Object.defineProperty( new Proxy({ bar: true }, { defineProperty: function () { return true; } }), "bar", { value: 5, configurable: false, writable: true, enumerable: true } ); return false; } catch(e) {} return passed;
}
§"getPrototypeOf" handler
?
function(){
var proxied = {}; var fakeProto = {}; var proxy = new Proxy(proxied, { getPrototypeOf: function (t) { return t === proxied && fakeProto; } }); return Object.getPrototypeOf(proxy) === fakeProto;
}
Yes
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Error
Error
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Error
Error
Error
Error
function(){
var proxied = {}; var fakeProto = {}; var proxy = new Proxy(proxied, { getPrototypeOf: function (t) { return t === proxied && fakeProto; } }); return Object.getPrototypeOf(proxy) === fakeProto;
}
§"getPrototypeOf" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // If the target object is not extensible, [[GetPrototypeOf]] applied to the proxy object // must return the same value as [[GetPrototypeOf]] applied to the proxy object's target object. try { Object.getPrototypeOf(new Proxy(Object.preventExtensions({}), { getPrototypeOf: function () { passed = true; return {}; } })); return false; } catch(e) {} return passed;
}
Yes
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Error
Error
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Error
Error
function(){
var passed = false; new Proxy({},{}); // If the target object is not extensible, [[GetPrototypeOf]] applied to the proxy object // must return the same value as [[GetPrototypeOf]] applied to the proxy object's target object. try { Object.getPrototypeOf(new Proxy(Object.preventExtensions({}), { getPrototypeOf: function () { passed = true; return {}; } })); return false; } catch(e) {} return passed;
}
§"setPrototypeOf" handler
?
function(){
var proxied = {}; var newProto = {}; var passed = false; Object.setPrototypeOf( new Proxy(proxied, { setPrototypeOf: function (t, p) { passed = t === proxied && p === newProto; return true; } }), newProto ); return passed;
}
Yes
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Error
Error
Error
Error
Error
Error
Error
Error
function(){
var proxied = {}; var newProto = {}; var passed = false; Object.setPrototypeOf( new Proxy(proxied, { setPrototypeOf: function (t, p) { passed = t === proxied && p === newProto; return true; } }), newProto ); return passed;
}
§"setPrototypeOf" handler invariant
?
function(){
var passed = false; new Proxy({},{}); Object.setPrototypeOf({},{}); // If the target object is not extensible, the argument value must be the // same as the result of [[GetPrototypeOf]] applied to target object. try { Object.setPrototypeOf( new Proxy(Object.preventExtensions({}), { setPrototypeOf: function () { passed = true; return true; } }),{}); return false; } catch(e) {} return passed;
}
Yes
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Error
Error
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Error
function(){
var passed = false; new Proxy({},{}); Object.setPrototypeOf({},{}); // If the target object is not extensible, the argument value must be the // same as the result of [[GetPrototypeOf]] applied to target object. try { Object.setPrototypeOf( new Proxy(Object.preventExtensions({}), { setPrototypeOf: function () { passed = true; return true; } }),{}); return false; } catch(e) {} return passed;
}
§"isExtensible" handler
?
function(){
var proxied = {}; var passed = false; Object.isExtensible( new Proxy(proxied, { isExtensible: function (t) { passed = t === proxied; return true; } }) ); return passed;
}
Yes
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Error
Error
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Error
function(){
var proxied = {}; var passed = false; Object.isExtensible( new Proxy(proxied, { isExtensible: function (t) { passed = t === proxied; return true; } }) ); return passed;
}
§"isExtensible" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // [[IsExtensible]] applied to the proxy object must return the same value // as [[IsExtensible]] applied to the proxy object's target object with the same argument. try { Object.isExtensible(new Proxy({}, { isExtensible: function (t) { passed = true; return false; } })); return false; } catch(e) {} try { Object.isExtensible(new Proxy(Object.preventExtensions({}), { isExtensible: function (t) { return true; } })); return false; } catch(e) {} return true;
}
Yes
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Error
Error
Error
Error
Error
Error
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function(){
var passed = false; new Proxy({},{}); // [[IsExtensible]] applied to the proxy object must return the same value // as [[IsExtensible]] applied to the proxy object's target object with the same argument. try { Object.isExtensible(new Proxy({}, { isExtensible: function (t) { passed = true; return false; } })); return false; } catch(e) {} try { Object.isExtensible(new Proxy(Object.preventExtensions({}), { isExtensible: function (t) { return true; } })); return false; } catch(e) {} return true;
}
§"preventExtensions" handler
?
function(){
var proxied = {}; var passed = false; Object.preventExtensions( new Proxy(proxied, { preventExtensions: function (t) { passed = t === proxied; return Object.preventExtensions(proxied); } }) ); return passed;
}
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Error
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function(){
var proxied = {}; var passed = false; Object.preventExtensions( new Proxy(proxied, { preventExtensions: function (t) { passed = t === proxied; return Object.preventExtensions(proxied); } }) ); return passed;
}
§"preventExtensions" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // [[PreventExtensions]] applied to the proxy object only returns true // if [[IsExtensible]] applied to the proxy object's target object is false. try { Object.preventExtensions(new Proxy({}, { preventExtensions: function () { passed = true; return true; } })); return false; } catch(e) {} return passed;
}
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function(){
var passed = false; new Proxy({},{}); // [[PreventExtensions]] applied to the proxy object only returns true // if [[IsExtensible]] applied to the proxy object's target object is false. try { Object.preventExtensions(new Proxy({}, { preventExtensions: function () { passed = true; return true; } })); return false; } catch(e) {} return passed;
}
§"ownKeys" handler
?
function(){
var proxied = {}; var passed = false; Object.keys( new Proxy(proxied, { ownKeys: function (t) { passed = t === proxied; return []; } }) ); return passed;
}
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function(){
var proxied = {}; var passed = false; Object.keys( new Proxy(proxied, { ownKeys: function (t) { passed = t === proxied; return []; } }) ); return passed;
}
§"ownKeys" handler invariant
?
function(){
var passed = false; new Proxy({},{}); // The Type of each result List element is either String or Symbol. try { Object.keys(new Proxy({}, { ownKeys: function () { passed = true; return [2]; }})); return false; } catch(e) {} // The result List must contain the keys of all non-configurable own properties of the target object. var proxied = {}; Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { Object.keys(new Proxy(proxied, { ownKeys: function () { return []; }})); return false; } catch(e) {} // If the target object is not extensible, then the result List must contain all the keys // of the own properties of the target object and no other values. try { Object.keys(new Proxy(Object.preventExtensions({b:1}), { ownKeys: function () { return ['a']; }})); return false; } catch(e) {} return passed;
}
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function(){
var passed = false; new Proxy({},{}); // The Type of each result List element is either String or Symbol. try { Object.keys(new Proxy({}, { ownKeys: function () { passed = true; return [2]; }})); return false; } catch(e) {} // The result List must contain the keys of all non-configurable own properties of the target object. var proxied = {}; Object.defineProperty(proxied, "foo", { value: 2, writable: true, enumerable: true }); try { Object.keys(new Proxy(proxied, { ownKeys: function () { return []; }})); return false; } catch(e) {} // If the target object is not extensible, then the result List must contain all the keys // of the own properties of the target object and no other values. try { Object.keys(new Proxy(Object.preventExtensions({b:1}), { ownKeys: function () { return ['a']; }})); return false; } catch(e) {} return passed;
}
§"apply" handler
?
function(){
var proxied = function(){}; var passed = false; var host = { method: new Proxy(proxied, { apply: function (t, thisArg, args) { passed = t === proxied && thisArg === host && args + "" === "foo,bar"; } }) }; host.method("foo", "bar"); return passed;
}
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function(){
var proxied = function(){}; var passed = false; var host = { method: new Proxy(proxied, { apply: function (t, thisArg, args) { passed = t === proxied && thisArg === host && args + "" === "foo,bar"; } }) }; host.method("foo", "bar"); return passed;
}
§"apply" handler invariant
?
function(){
var passed = false; new Proxy(function(){}, { apply: function () { passed = true; } })(); // A Proxy exotic object only has a [[Call]] internal method if the // initial value of its [[ProxyTarget]] internal slot is an object // that has a [[Call]] internal method. try { new Proxy({}, { apply: function () {} })(); return false; } catch(e) {} return passed;
}
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function(){
var passed = false; new Proxy(function(){}, { apply: function () { passed = true; } })(); // A Proxy exotic object only has a [[Call]] internal method if the // initial value of its [[ProxyTarget]] internal slot is an object // that has a [[Call]] internal method. try { new Proxy({}, { apply: function () {} })(); return false; } catch(e) {} return passed;
}
§"construct" handler
?
function(){
var proxied = function(){}; var passed = false; new new Proxy(proxied, { construct: function (t, args) { passed = t === proxied && args + "" === "foo,bar"; return {}; } })("foo","bar"); return passed;
}
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function(){
var proxied = function(){}; var passed = false; new new Proxy(proxied, { construct: function (t, args) { passed = t === proxied && args + "" === "foo,bar"; return {}; } })("foo","bar"); return passed;
}
§"construct" handler invariants
?
function(){
var passed = false; new Proxy({},{}); // A Proxy exotic object only has a [[Construct]] internal method if the // initial value of its [[ProxyTarget]] internal slot is an object // that has a [[Construct]] internal method. try { new new Proxy({}, { construct: function (t, args) { return {}; } })(); return false; } catch(e) {} // The result of [[Construct]] must be an Object. try { new new Proxy(function(){}, { construct: function (t, args) { passed = true; return 5; } })(); return false; } catch(e) {} return passed;
}
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function(){
var passed = false; new Proxy({},{}); // A Proxy exotic object only has a [[Construct]] internal method if the // initial value of its [[ProxyTarget]] internal slot is an object // that has a [[Construct]] internal method. try { new new Proxy({}, { construct: function (t, args) { return {}; } })(); return false; } catch(e) {} // The result of [[Construct]] must be an Object. try { new new Proxy(function(){}, { construct: function (t, args) { passed = true; return 5; } })(); return false; } catch(e) {} return passed;
}
§Proxy.revocable
?
function(){
var obj = Proxy.revocable({}, { get: function() { return 5; } }); var passed = (obj.proxy.foo === 5); obj.revoke(); try { obj.proxy.foo; } catch(e) { passed &= e instanceof TypeError; } return passed;
}
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function(){
var obj = Proxy.revocable({}, { get: function() { return 5; } }); var passed = (obj.proxy.foo === 5); obj.revoke(); try { obj.proxy.foo; } catch(e) { passed &= e instanceof TypeError; } return passed;
}
§Array.isArray support
?
function(){
return Array.isArray(new Proxy([], {}));
}
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function(){
return Array.isArray(new Proxy([], {}));
}
§JSON.stringify support
?
function(){
return JSON.stringify(new Proxy(['foo'], {})) === '["foo"]';
}
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function(){
return JSON.stringify(new Proxy(['foo'], {})) === '["foo"]';
}

Reflect

§Reflect.get
?
function(){
return Reflect.get({ qux: 987 }, "qux") === 987;
}
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function(){
return Reflect.get({ qux: 987 }, "qux") === 987;
}
§Reflect.set
?
function(){
var obj = {}; Reflect.set(obj, "quux", 654); return obj.quux === 654;
}
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function(){
var obj = {}; Reflect.set(obj, "quux", 654); return obj.quux === 654;
}
§Reflect.has
?
function(){
return Reflect.has({ qux: 987 }, "qux");
}
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function(){
return Reflect.has({ qux: 987 }, "qux");
}
§Reflect.deleteProperty
?
function(){
var obj = { bar: 456 }; Reflect.deleteProperty(obj, "bar"); return !("bar" in obj);
}
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function(){
var obj = { bar: 456 }; Reflect.deleteProperty(obj, "bar"); return !("bar" in obj);
}
§Reflect.getOwnPropertyDescriptor
?
function(){
var obj = { baz: 789 }; var desc = Reflect.getOwnPropertyDescriptor(obj, "baz"); return desc.value === 789 && desc.configurable && desc.writable && desc.enumerable;
}
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function(){
var obj = { baz: 789 }; var desc = Reflect.getOwnPropertyDescriptor(obj, "baz"); return desc.value === 789 && desc.configurable && desc.writable && desc.enumerable;
}
§Reflect.defineProperty
?
function(){
var obj = {}; Reflect.defineProperty(obj, "foo", { value: 123 }); return obj.foo === 123 && Reflect.defineProperty(Object.freeze({}), "foo", { value: 123 }) === false;
}
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function(){
var obj = {}; Reflect.defineProperty(obj, "foo", { value: 123 }); return obj.foo === 123 && Reflect.defineProperty(Object.freeze({}), "foo", { value: 123 }) === false;
}
§Reflect.getPrototypeOf
?
function(){
return Reflect.getPrototypeOf([]) === Array.prototype;
}
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Error
Error
Error
Error
Error
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Error
Error
function(){
return Reflect.getPrototypeOf([]) === Array.prototype;
}
§Reflect.setPrototypeOf
?
function(){
var obj = {}; Reflect.setPrototypeOf(obj, Array.prototype); return obj instanceof Array;
}
Yes
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Error
Error
Error
Error
Error
Error
Error
Error
function(){
var obj = {}; Reflect.setPrototypeOf(obj, Array.prototype); return obj instanceof Array;
}
§Reflect.isExtensible
?
function(){
return Reflect.isExtensible({}) && !Reflect.isExtensible(Object.preventExtensions({}));
}
Yes
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Error
Error
Error
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Error
Error
Error
Error
function(){
return Reflect.isExtensible({}) && !Reflect.isExtensible(Object.preventExtensions({}));
}
§Reflect.preventExtensions
?
function(){
var obj = {}; Reflect.preventExtensions(obj); return !Object.isExtensible(obj);
}
Yes
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Error
Error
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Error
Error
Error
function(){
var obj = {}; Reflect.preventExtensions(obj); return !Object.isExtensible(obj);
}
§Reflect.ownKeys, string keys
?
function(){
var obj = Object.create({ C: true }); obj.A = true; Object.defineProperty(obj, 'B', { value: true, enumerable: false }); return Reflect.ownKeys(obj).sort() + '' === "A,B";
}
Yes
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Error
Error
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Error
function(){
var obj = Object.create({ C: true }); obj.A = true; Object.defineProperty(obj, 'B', { value: true, enumerable: false }); return Reflect.ownKeys(obj).sort() + '' === "A,B";
}
§Reflect.ownKeys, symbol keys
?
function(){
var s1 = Symbol(), s2 = Symbol(), s3 = Symbol(); var proto = {}; proto[s1] = true; var obj = Object.create(proto); obj[s2] = true; Object.defineProperty(obj, s3, { value: true, enumerable: false }); var keys = Reflect.ownKeys(obj); return keys.indexOf(s2) >-1 && keys.indexOf(s3) >-1 && keys.length === 2;
}
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Error
Error
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Error
function(){
var s1 = Symbol(), s2 = Symbol(), s3 = Symbol(); var proto = {}; proto[s1] = true; var obj = Object.create(proto); obj[s2] = true; Object.defineProperty(obj, s3, { value: true, enumerable: false }); var keys = Reflect.ownKeys(obj); return keys.indexOf(s2) >-1 && keys.indexOf(s3) >-1 && keys.length === 2;
}
§Reflect.apply
?
function(){
return Reflect.apply(Array.prototype.push, [1,2], [3,4,5]) === 5;
}
Yes
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Error
Error
Error
Error
Error
Error
Error
Error
function(){
return Reflect.apply(Array.prototype.push, [1,2], [3,4,5]) === 5;
}
§Reflect.construct
?
function(){
return Reflect.construct(function(a, b, c) { this.qux = a + b + c; }, ["foo", "bar", "baz"]).qux === "foobarbaz";
}
Yes
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Error
Error
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Error
function(){
return Reflect.construct(function(a, b, c) { this.qux = a + b + c; }, ["foo", "bar", "baz"]).qux === "foobarbaz";
}
§Reflect.construct sets new.target meta-property
?
function(){
return Reflect.construct(function(a, b, c) { if (new.target === Object) { this.qux = a + b + c; } }, ["foo", "bar", "baz"], Object).qux === "foobarbaz";
}
Yes
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Error
Error
Error
Error
Error
Error
Error
Error
function(){
return Reflect.construct(function(a, b, c) { if (new.target === Object) { this.qux = a + b + c; } }, ["foo", "bar", "baz"], Object).qux === "foobarbaz";
}
§Reflect.construct creates instances from third argument
?
function(){
function F(){} var obj = Reflect.construct(function(){ this.y = 1; }, [], F); return obj.y === 1 && obj instanceof F;
}
Yes
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Error
Error
Error
Error
Error
Error
Error
Error
function(){
function F(){} var obj = Reflect.construct(function(){ this.y = 1; }, [], F); return obj.y === 1 && obj instanceof F;
}
§Reflect.construct, Array subclassing
?
function(){
function F(){} var obj = Reflect.construct(Array, [], F); obj[2] = 'foo'; return obj.length === 3 && obj instanceof F;
}
Yes
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Error
Error
Error
Error
Error
Error
Error
Error
function(){
function F(){} var obj = Reflect.construct(Array, [], F); obj[2] = 'foo'; return obj.length === 3 && obj instanceof F;
}
§Reflect.construct, RegExp subclassing
?
function(){
function F(){} var obj = Reflect.construct(RegExp, ["baz","g"], F); return RegExp.prototype.exec.call(obj, "foobarbaz")[0] === "baz" && obj.lastIndex === 9 && obj instanceof F;
}
Yes
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Error
Error
Error
Error
Error
Error
Error
Error
function(){
function F(){} var obj = Reflect.construct(RegExp, ["baz","g"], F); return RegExp.prototype.exec.call(obj, "foobarbaz")[0] === "baz" && obj.lastIndex === 9 && obj instanceof F;
}
§Reflect.construct, Function subclassing
?
function(){
function F(){} var obj = Reflect.construct(Function, ["return 2"], F); return obj() === 2 && obj instanceof F;
}
Yes
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Error
Error
Error
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Error
Error
Error
Error
function(){
function F(){} var obj = Reflect.construct(Function, ["return 2"], F); return obj() === 2 && obj instanceof F;
}
§Reflect.construct, Promise subclassing
?
function(){
function F(){} var p1 = Reflect.construct(Promise,[function(resolve, reject) { resolve("foo"); }], F); var p2 = Reflect.construct(Promise,[function(resolve, reject) { reject("quux"); }], F); var score = +(p1 instanceof F && p2 instanceof F); function thenFn(result) { score += (result === "foo"); check(); } function catchFn(result) { score += (result === "quux"); check(); } function shouldNotRun(result) { score = -Infinity; } p1.then = p2.then = Promise.prototype.then; p1.catch = p2.catch = Promise.prototype.catch; p1.then(thenFn, shouldNotRun); p2.then(shouldNotRun, catchFn); p1.catch(shouldNotRun); p2.catch(catchFn); function check() { if (score === 4) asyncTestPassed(); }
}
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Error
Error
Error
Error
Error
Error
Error
Error
function(){
function F(){} var p1 = Reflect.construct(Promise,[function(resolve, reject) { resolve("foo"); }], F); var p2 = Reflect.construct(Promise,[function(resolve, reject) { reject("quux"); }], F); var score = +(p1 instanceof F && p2 instanceof F); function thenFn(result) { score += (result === "foo"); check(); } function catchFn(result) { score += (result === "quux"); check(); } function shouldNotRun(result) { score = -Infinity; } p1.then = p2.then = Promise.prototype.then; p1.catch = p2.catch = Promise.prototype.catch; p1.then(thenFn, shouldNotRun); p2.then(shouldNotRun, catchFn); p1.catch(shouldNotRun); p2.catch(catchFn); function check() { if (score === 4) asyncTestPassed(); }
}

Promise

§basic functionality
?
function(){
var p1 = new Promise(function(resolve, reject) { resolve("foo"); }); var p2 = new Promise(function(resolve, reject) { reject("quux"); }); var score = 0; function thenFn(result) { score += (result === "foo"); check(); } function catchFn(result) { score += (result === "quux"); check(); } function shouldNotRun(result) { score = -Infinity; } p1.then(thenFn, shouldNotRun); p2.then(shouldNotRun, catchFn); p1.catch(shouldNotRun); p2.catch(catchFn); p1.then(function() { // Promise.prototype.then() should return a new Promise score += p1.then() !== p1; check(); }); function check() { if (score === 4) asyncTestPassed(); }
}
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Error
Error
function(){
var p1 = new Promise(function(resolve, reject) { resolve("foo"); }); var p2 = new Promise(function(resolve, reject) { reject("quux"); }); var score = 0; function thenFn(result) { score += (result === "foo"); check(); } function catchFn(result) { score += (result === "quux"); check(); } function shouldNotRun(result) { score = -Infinity; } p1.then(thenFn, shouldNotRun); p2.then(shouldNotRun, catchFn); p1.catch(shouldNotRun); p2.catch(catchFn); p1.then(function() { // Promise.prototype.then() should return a new Promise score += p1.then() !== p1; check(); }); function check() { if (score === 4) asyncTestPassed(); }
}
§constructor requires new
?
function(){
new Promise(function(){}); try { Promise(function(){}); return false; } catch(e) { return true; }
}
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Error
Error
function(){
new Promise(function(){}); try { Promise(function(){}); return false; } catch(e) { return true; }
}
§Promise.prototype isn't an instance
?
function(){
new Promise(function(){}); try { Promise.prototype.then(function(){}); } catch (e) { return true; }
}
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Error
Error
function(){
new Promise(function(){}); try { Promise.prototype.then(function(){}); } catch (e) { return true; }
}
§Promise.all
?
function(){
var fulfills = Promise.all([ new Promise(function(resolve) { setTimeout(resolve,2000,"foo"); }), new Promise(function(resolve) { setTimeout(resolve,1000,"bar"); }) ]); var rejects = Promise.all([ new Promise(function(_, reject) { setTimeout(reject, 2000,"baz"); }), new Promise(function(_, reject) { setTimeout(reject, 1000,"qux"); }) ]); var score = 0; fulfills.then(function(result) { score += (result + "" === "foo,bar"); check(); }); rejects.catch(function(result) { score += (result === "qux"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
Yes
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Error
Error
function(){
var fulfills = Promise.all([ new Promise(function(resolve) { setTimeout(resolve,2000,"foo"); }), new Promise(function(resolve) { setTimeout(resolve,1000,"bar"); }) ]); var rejects = Promise.all([ new Promise(function(_, reject) { setTimeout(reject, 2000,"baz"); }), new Promise(function(_, reject) { setTimeout(reject, 1000,"qux"); }) ]); var score = 0; fulfills.then(function(result) { score += (result + "" === "foo,bar"); check(); }); rejects.catch(function(result) { score += (result === "qux"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
§Promise.all, generic iterables
?
function(){
var fulfills = Promise.all(global.__createIterableObject([ new Promise(function(resolve) { setTimeout(resolve,2000,"foo"); }), new Promise(function(resolve) { setTimeout(resolve,1000,"bar"); }) ])); var rejects = Promise.all(global.__createIterableObject([ new Promise(function(_, reject) { setTimeout(reject, 2000,"baz"); }), new Promise(function(_, reject) { setTimeout(reject, 1000,"qux"); }) ])); var score = 0; fulfills.then(function(result) { score += (result + "" === "foo,bar"); check(); }); rejects.catch(function(result) { score += (result === "qux"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
Yes
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No
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Error
Error
function(){
var fulfills = Promise.all(global.__createIterableObject([ new Promise(function(resolve) { setTimeout(resolve,2000,"foo"); }), new Promise(function(resolve) { setTimeout(resolve,1000,"bar"); }) ])); var rejects = Promise.all(global.__createIterableObject([ new Promise(function(_, reject) { setTimeout(reject, 2000,"baz"); }), new Promise(function(_, reject) { setTimeout(reject, 1000,"qux"); }) ])); var score = 0; fulfills.then(function(result) { score += (result + "" === "foo,bar"); check(); }); rejects.catch(function(result) { score += (result === "qux"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
§Promise.race
?
function(){
var fulfills = Promise.race([ new Promise(function(resolve) { setTimeout(resolve,1000,"foo"); }), new Promise(function(_, reject) { setTimeout(reject, 2000,"bar"); }) ]); var rejects = Promise.race([ new Promise(function(_, reject) { setTimeout(reject, 1000,"baz"); }), new Promise(function(resolve) { setTimeout(resolve,2000,"qux"); }) ]); var score = 0; fulfills.then(function(result) { score += (result === "foo"); check(); }); rejects.catch(function(result) { score += (result === "baz"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
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Error
Error
function(){
var fulfills = Promise.race([ new Promise(function(resolve) { setTimeout(resolve,1000,"foo"); }), new Promise(function(_, reject) { setTimeout(reject, 2000,"bar"); }) ]); var rejects = Promise.race([ new Promise(function(_, reject) { setTimeout(reject, 1000,"baz"); }), new Promise(function(resolve) { setTimeout(resolve,2000,"qux"); }) ]); var score = 0; fulfills.then(function(result) { score += (result === "foo"); check(); }); rejects.catch(function(result) { score += (result === "baz"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
§Promise.race, generic iterables
?
function(){
var fulfills = Promise.race(global.__createIterableObject([ new Promise(function(resolve) { setTimeout(resolve,1000,"foo"); }), new Promise(function(_, reject) { setTimeout(reject, 2000,"bar"); }) ])); var rejects = Promise.race(global.__createIterableObject([ new Promise(function(_, reject) { setTimeout(reject, 1000,"baz"); }), new Promise(function(resolve) { setTimeout(resolve,2000,"qux"); }) ])); var score = 0; fulfills.then(function(result) { score += (result === "foo"); check(); }); rejects.catch(function(result) { score += (result === "baz"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
Yes
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No
No
Error
Error
function(){
var fulfills = Promise.race(global.__createIterableObject([ new Promise(function(resolve) { setTimeout(resolve,1000,"foo"); }), new Promise(function(_, reject) { setTimeout(reject, 2000,"bar"); }) ])); var rejects = Promise.race(global.__createIterableObject([ new Promise(function(_, reject) { setTimeout(reject, 1000,"baz"); }), new Promise(function(resolve) { setTimeout(resolve,2000,"qux"); }) ])); var score = 0; fulfills.then(function(result) { score += (result === "foo"); check(); }); rejects.catch(function(result) { score += (result === "baz"); check(); }); function check() { if (score === 2) asyncTestPassed(); }
}
§Promise[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(Promise, Symbol.species); return 'get' in prop && Promise[Symbol.species] === Promise;
}
Yes
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Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var prop = Object.getOwnPropertyDescriptor(Promise, Symbol.species); return 'get' in prop && Promise[Symbol.species] === Promise;
}

Symbol

§basic functionality
?
function(){
var object = {}; var symbol = Symbol(); var value = {}; object[symbol] = value; return object[symbol] === value;
}
Yes
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Yes
Error
Error
function(){
var object = {}; var symbol = Symbol(); var value = {}; object[symbol] = value; return object[symbol] === value;
}
§typeof support
?
function(){
return typeof Symbol() === "symbol";
}
Yes
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Yes
Error
Error
function(){
return typeof Symbol() === "symbol";
}
§symbol keys are hidden to pre-ES6 code
?
function(){
var object = {}; var symbol = Symbol(); object[symbol] = 1; for (var x in object){} var passed = !x; if (Object.keys && Object.getOwnPropertyNames) { passed &= Object.keys(object).length === 0 && Object.getOwnPropertyNames(object).length === 0; } return passed;
}
Yes
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Yes
Yes
Error
Error
function(){
var object = {}; var symbol = Symbol(); object[symbol] = 1; for (var x in object){} var passed = !x; if (Object.keys && Object.getOwnPropertyNames) { passed &= Object.keys(object).length === 0 && Object.getOwnPropertyNames(object).length === 0; } return passed;
}
§Object.defineProperty support
?
function(){
var object = {}; var symbol = Symbol(); var value = {}; if (Object.defineProperty) { Object.defineProperty(object, symbol, { value: value }); return object[symbol] === value; } return passed;
}
Yes
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Yes
Error
Error
function(){
var object = {}; var symbol = Symbol(); var value = {}; if (Object.defineProperty) { Object.defineProperty(object, symbol, { value: value }); return object[symbol] === value; } return passed;
}
§symbols inherit from Symbol.prototype
?
function(){
var symbol = Symbol(); var passed = symbol.foo === void undefined; Symbol.prototype.foo = 2; passed &= symbol.foo === 2; delete Symbol.prototype.foo; return passed;
}
Yes
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Yes
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Yes
Yes
Error
Error
function(){
var symbol = Symbol(); var passed = symbol.foo === void undefined; Symbol.prototype.foo = 2; passed &= symbol.foo === 2; delete Symbol.prototype.foo; return passed;
}
§cannot coerce to string or number
?
function(){
var symbol = Symbol(); try { symbol + ""; return false; } catch(e) {} try { symbol + 0; return false; } catch(e) {} return true;
}
Yes
Yes
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Yes
Yes
Yes
Error
Error
function(){
var symbol = Symbol(); try { symbol + ""; return false; } catch(e) {} try { symbol + 0; return false; } catch(e) {} return true;
}
§can convert with String()
?
function(){
return String(Symbol("foo")) === "Symbol(foo)";
}
Yes
Yes
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Yes
Yes
Error
Error
Error
Error
function(){
return String(Symbol("foo")) === "Symbol(foo)";
}
§new Symbol() throws
?
function(){
var symbol = Symbol(); try { new Symbol(); } catch(e) { return true; }
}
Yes
Yes
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Yes
Yes
Error
Error
function(){
var symbol = Symbol(); try { new Symbol(); } catch(e) { return true; }
}
§Object(symbol)
?
function(){
var symbol = Symbol(); var symbolObject = Object(symbol); return typeof symbolObject === "object" && symbolObject instanceof Symbol && symbolObject == symbol && // eslint-disable-line eqeqeq symbolObject !== symbol && symbolObject.valueOf() === symbol;
}
Yes
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No
No
No
No
No
No
Error
Error
function(){
var symbol = Symbol(); var symbolObject = Object(symbol); return typeof symbolObject === "object" && symbolObject instanceof Symbol && symbolObject == symbol && // eslint-disable-line eqeqeq symbolObject !== symbol && symbolObject.valueOf() === symbol;
}
§JSON.stringify ignores symbol primitives
?
function(){
var object = { foo: Symbol() }; object[Symbol()] = 1; var array = [Symbol()]; return JSON.stringify(object) === '{}' && JSON.stringify(array) === '[null]' && JSON.stringify(Symbol()) === void undefined;
}
Yes
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Yes
Error
Error
function(){
var object = { foo: Symbol() }; object[Symbol()] = 1; var array = [Symbol()]; return JSON.stringify(object) === '{}' && JSON.stringify(array) === '[null]' && JSON.stringify(Symbol()) === void undefined;
}
§JSON.stringify ignores symbol objects
?
function(){
var testSymbolObject = function (sym) { var object = { foo: sym }; try { // some browsers throw a TypeError when setting symbol object keys. // this isn't part of this test, so, ignore it if so. object[sym] = 1; } catch (e) {} // some browsers throw a TypeError when setting symbol object keys. var array = [sym]; return JSON.stringify(object) === '{"foo":{}}' && JSON.stringify(array) === '[{}]' && JSON.stringify(sym) === '{}'; }; var objSym = Object(Symbol()); var symNoToJSON = Object(Symbol()); Object.defineProperty(symNoToJSON, 'toJSON', { enumerable: false, value: null }); // ensure it overrides the prototype, but is not callable return testSymbolObject(objSym) && testSymbolObject(symNoToJSON);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
var testSymbolObject = function (sym) { var object = { foo: sym }; try { // some browsers throw a TypeError when setting symbol object keys. // this isn't part of this test, so, ignore it if so. object[sym] = 1; } catch (e) {} // some browsers throw a TypeError when setting symbol object keys. var array = [sym]; return JSON.stringify(object) === '{"foo":{}}' && JSON.stringify(array) === '[{}]' && JSON.stringify(sym) === '{}'; }; var objSym = Object(Symbol()); var symNoToJSON = Object(Symbol()); Object.defineProperty(symNoToJSON, 'toJSON', { enumerable: false, value: null }); // ensure it overrides the prototype, but is not callable return testSymbolObject(objSym) && testSymbolObject(symNoToJSON);
}
§global symbol registry
?
function(){
var symbol = Symbol.for('foo'); return Symbol.for('foo') === symbol && Symbol.keyFor(symbol) === 'foo';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var symbol = Symbol.for('foo'); return Symbol.for('foo') === symbol && Symbol.keyFor(symbol) === 'foo';
}

well-known symbols

§Symbol.hasInstance
?
function(){
var passed = false; var obj = { foo: true }; var C = function(){}; Object.defineProperty(C, Symbol.hasInstance, { value: function(inst) { passed = inst.foo; return false; } }); obj instanceof C; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
function(){
var passed = false; var obj = { foo: true }; var C = function(){}; Object.defineProperty(C, Symbol.hasInstance, { value: function(inst) { passed = inst.foo; return false; } }); obj instanceof C; return passed;
}
§Symbol.isConcatSpreadable, non-spreadable array
?
function(){
var a = [], b = []; b[Symbol.isConcatSpreadable] = false; a = a.concat(b); return a[0] === b;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
var a = [], b = []; b[Symbol.isConcatSpreadable] = false; a = a.concat(b); return a[0] === b;
}
§Symbol.isConcatSpreadable, spreadable object with poisoned getter
?
function(){
if (typeof Symbol !== 'function' || !Symbol.isConcatSpreadable) { return null; } var spreadableHasPoisonedIndex = { length: Math.pow(2, 53) - 1 }; spreadableHasPoisonedIndex[Symbol.isConcatSpreadable] = true; Object.defineProperty(spreadableHasPoisonedIndex, 0, { get: function () { throw new SyntaxError(); } }); try { [].concat(spreadableHasPoisonedIndex); return false; } catch (e) { return !!e && e.name === 'SyntaxError'; }
}
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
function(){
if (typeof Symbol !== 'function' || !Symbol.isConcatSpreadable) { return null; } var spreadableHasPoisonedIndex = { length: Math.pow(2, 53) - 1 }; spreadableHasPoisonedIndex[Symbol.isConcatSpreadable] = true; Object.defineProperty(spreadableHasPoisonedIndex, 0, { get: function () { throw new SyntaxError(); } }); try { [].concat(spreadableHasPoisonedIndex); return false; } catch (e) { return !!e && e.name === 'SyntaxError'; }
}
§Symbol.iterator, existence
?
function(){
return "iterator" in Symbol;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
return "iterator" in Symbol;
}
§Symbol.iterator, arguments object
?
function(){
return (function() { return typeof arguments[Symbol.iterator] === 'function' && Object.hasOwnProperty.call(arguments, Symbol.iterator); }());
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
function(){
return (function() { return typeof arguments[Symbol.iterator] === 'function' && Object.hasOwnProperty.call(arguments, Symbol.iterator); }());
}
§Symbol.species, existence
?
function(){
return "species" in Symbol;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
function(){
return "species" in Symbol;
}
§Symbol.species, Array.prototype.concat
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.concat.call(obj, []).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.concat.call(obj, []).foo === 1;
}
§Symbol.species, Array.prototype.filter
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.filter.call(obj, Boolean).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.filter.call(obj, Boolean).foo === 1;
}
§Symbol.species, Array.prototype.map
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.map.call(obj, Boolean).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.map.call(obj, Boolean).foo === 1;
}
§Symbol.species, Array.prototype.slice
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.slice.call(obj, 0).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.slice.call(obj, 0).foo === 1;
}
§Symbol.species, Array.prototype.splice
?
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.splice.call(obj, 0).foo === 1;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
function(){
var obj = []; obj.constructor = {}; obj.constructor[Symbol.species] = function() { return { foo: 1 }; }; return Array.prototype.splice.call(obj, 0).foo === 1;
}
§Symbol.species, RegExp.prototype[Symbol.split]
?
function(){
var passed = false; var obj = { constructor: {} }; obj[Symbol.split] = RegExp.prototype[Symbol.split]; obj.constructor[Symbol.species] = function() { passed = true; return /./; }; "".split(obj); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
No
No
No
No
No
No
Error
Error
function(){
var passed = false; var obj = { constructor: {} }; obj[Symbol.split] = RegExp.prototype[Symbol.split]; obj.constructor[Symbol.species] = function() { passed = true; return /./; }; "".split(obj); return passed;
}
§Symbol.species, Promise.prototype.then
?
function(){
var promise = new Promise(function(resolve){ resolve(42); }); var FakePromise1 = promise.constructor = function(exec){ exec(function(){}, function(){}); }; var FakePromise2 = function(exec){ exec(function(){}, function(){}); }; Object.defineProperty(FakePromise1, Symbol.species, {value: FakePromise2}); return promise.then(function(){}) instanceof FakePromise2;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
Error
Error
function(){
var promise = new Promise(function(resolve){ resolve(42); }); var FakePromise1 = promise.constructor = function(exec){ exec(function(){}, function(){}); }; var FakePromise2 = function(exec){ exec(function(){}, function(){}); }; Object.defineProperty(FakePromise1, Symbol.species, {value: FakePromise2}); return promise.then(function(){}) instanceof FakePromise2;
}
§Symbol.replace
?
function(){
var O = {}; O[Symbol.replace] = function(){ return 42; }; return ''.replace(O) === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
var O = {}; O[Symbol.replace] = function(){ return 42; }; return ''.replace(O) === 42;
}
§Symbol.search
?
function(){
var O = {}; O[Symbol.search] = function(){ return 42; }; return ''.search(O) === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
var O = {}; O[Symbol.search] = function(){ return 42; }; return ''.search(O) === 42;
}
§Symbol.split
?
function(){
var O = {}; O[Symbol.split] = function(){ return 42; }; return ''.split(O) === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
var O = {}; O[Symbol.split] = function(){ return 42; }; return ''.split(O) === 42;
}
§Symbol.match
?
function(){
var O = {}; O[Symbol.match] = function(){ return 42; }; return ''.match(O) === 42;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
var O = {}; O[Symbol.match] = function(){ return 42; }; return ''.match(O) === 42;
}
§Symbol.match, RegExp constructor
?
function(){
var re = /./; re[Symbol.match] = false; var foo = {constructor: RegExp}; foo[Symbol.match] = true; return RegExp(re) !== re && RegExp(foo) === foo;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
var re = /./; re[Symbol.match] = false; var foo = {constructor: RegExp}; foo[Symbol.match] = true; return RegExp(re) !== re && RegExp(foo) === foo;
}
§Symbol.match, String.prototype.startsWith
?
function(){
var re = /./; try { '/./'.startsWith(re); } catch(e){ re[Symbol.match] = false; return '/./'.startsWith(re); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var re = /./; try { '/./'.startsWith(re); } catch(e){ re[Symbol.match] = false; return '/./'.startsWith(re); }
}
§Symbol.match, String.prototype.endsWith
?
function(){
var re = /./; try { '/./'.endsWith(re); } catch(e){ re[Symbol.match] = false; return '/./'.endsWith(re); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var re = /./; try { '/./'.endsWith(re); } catch(e){ re[Symbol.match] = false; return '/./'.endsWith(re); }
}
§Symbol.match, String.prototype.includes
?
function(){
var re = /./; try { '/./'.includes(re); } catch(e){ re[Symbol.match] = false; return '/./'.includes(re); }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var re = /./; try { '/./'.includes(re); } catch(e){ re[Symbol.match] = false; return '/./'.includes(re); }
}
§Symbol.toPrimitive
?
function(){
var a = {}, b = {}, c = {}; var passed = 0; a[Symbol.toPrimitive] = function(hint) { passed += hint === "number"; return 0; }; b[Symbol.toPrimitive] = function(hint) { passed += hint === "string"; return 0; }; c[Symbol.toPrimitive] = function(hint) { passed += hint === "default"; return 0; }; a >= 0; b in {}; c == 0; // eslint-disable-line eqeqeq return passed === 3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
var a = {}, b = {}, c = {}; var passed = 0; a[Symbol.toPrimitive] = function(hint) { passed += hint === "number"; return 0; }; b[Symbol.toPrimitive] = function(hint) { passed += hint === "string"; return 0; }; c[Symbol.toPrimitive] = function(hint) { passed += hint === "default"; return 0; }; a >= 0; b in {}; c == 0; // eslint-disable-line eqeqeq return passed === 3;
}
§Symbol.toStringTag
?
function(){
var a = {}; a[Symbol.toStringTag] = "foo"; return (a + "") === "[object foo]";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
Error
Error
function(){
var a = {}; a[Symbol.toStringTag] = "foo"; return (a + "") === "[object foo]";
}
§Symbol.toStringTag affects existing built-ins
?
function(){
var s = Symbol.toStringTag; var passed = true; [ [Array.prototype, []], [String.prototype, ''], [arguments, arguments], [Function.prototype, function(){}], [Error.prototype, new Error()], [Boolean.prototype, true], [Number.prototype, 2], [Date.prototype, new Date()], [RegExp.prototype, /./] ].forEach(function(pair){ pair[0][s] = "foo"; passed &= (Object.prototype.toString.call(pair[1]) === "[object foo]"); delete pair[0][s]; }); return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
Error
Error
function(){
var s = Symbol.toStringTag; var passed = true; [ [Array.prototype, []], [String.prototype, ''], [arguments, arguments], [Function.prototype, function(){}], [Error.prototype, new Error()], [Boolean.prototype, true], [Number.prototype, 2], [Date.prototype, new Date()], [RegExp.prototype, /./] ].forEach(function(pair){ pair[0][s] = "foo"; passed &= (Object.prototype.toString.call(pair[1]) === "[object foo]"); delete pair[0][s]; }); return passed;
}
§Symbol.toStringTag, new built-ins
?
function(){
var passed = true; var s = Symbol.toStringTag; [ [String, "String Iterator"], [Array, "Array Iterator"], [Map, "Map Iterator"], [Set, "Set Iterator"] ].forEach(function(pair){ var iterProto = Object.getPrototypeOf(new pair[0]()[Symbol.iterator]()); passed = passed && iterProto.hasOwnProperty(s) && iterProto[s] === pair[1]; }); passed = passed && Object.getPrototypeOf(function*(){})[s] === "GeneratorFunction" && Object.getPrototypeOf(function*(){}())[s] === "Generator" && Map.prototype[s] === "Map" && Set.prototype[s] === "Set" && ArrayBuffer.prototype[s] === "ArrayBuffer" && DataView.prototype[s] === "DataView" && Promise.prototype[s] === "Promise" && Symbol.prototype[s] === "Symbol" && typeof Object.getOwnPropertyDescriptor( Object.getPrototypeOf(Int8Array).prototype, Symbol.toStringTag).get === "function"; return passed;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Error
No
Error
Error
No
Error
Error
function(){
var passed = true; var s = Symbol.toStringTag; [ [String, "String Iterator"], [Array, "Array Iterator"], [Map, "Map Iterator"], [Set, "Set Iterator"] ].forEach(function(pair){ var iterProto = Object.getPrototypeOf(new pair[0]()[Symbol.iterator]()); passed = passed && iterProto.hasOwnProperty(s) && iterProto[s] === pair[1]; }); passed = passed && Object.getPrototypeOf(function*(){})[s] === "GeneratorFunction" && Object.getPrototypeOf(function*(){}())[s] === "Generator" && Map.prototype[s] === "Map" && Set.prototype[s] === "Set" && ArrayBuffer.prototype[s] === "ArrayBuffer" && DataView.prototype[s] === "DataView" && Promise.prototype[s] === "Promise" && Symbol.prototype[s] === "Symbol" && typeof Object.getOwnPropertyDescriptor( Object.getPrototypeOf(Int8Array).prototype, Symbol.toStringTag).get === "function"; return passed;
}
§Symbol.toStringTag, misc. built-ins
?
function(){
var s = Symbol.toStringTag; return Math[s] === "Math" && JSON[s] === "JSON";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
Flag
No
No
Error
Error
function(){
var s = Symbol.toStringTag; return Math[s] === "Math" && JSON[s] === "JSON";
}
§Symbol.unscopables
?
function(){
var a = { foo: 1, bar: 2 }; a[Symbol.unscopables] = { bar: true }; with (a) { return foo === 1 && typeof bar === "undefined"; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var a = { foo: 1, bar: 2 }; a[Symbol.unscopables] = { bar: true }; with (a) { return foo === 1 && typeof bar === "undefined"; }
}

built-in extensions

Object static methods

§Object.assign
?
function(){
var o = Object.assign({a:true}, {b:true}, {c:true}); return "a" in o && "b" in o && "c" in o;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var o = Object.assign({a:true}, {b:true}, {c:true}); return "a" in o && "b" in o && "c" in o;
}
§Object.is
?
function(){
return typeof Object.is === 'function' && Object.is(NaN, NaN) && !Object.is(-0, 0);
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
function(){
return typeof Object.is === 'function' && Object.is(NaN, NaN) && !Object.is(-0, 0);
}
§Object.getOwnPropertySymbols
?
function(){
var o = {}; var sym = Symbol(), sym2 = Symbol(), sym3 = Symbol(); o[sym] = true; o[sym2] = true; o[sym3] = true; var result = Object.getOwnPropertySymbols(o); return result[0] === sym && result[1] === sym2 && result[2] === sym3;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
var o = {}; var sym = Symbol(), sym2 = Symbol(), sym3 = Symbol(); o[sym] = true; o[sym2] = true; o[sym3] = true; var result = Object.getOwnPropertySymbols(o); return result[0] === sym && result[1] === sym2 && result[2] === sym3;
}
§Object.setPrototypeOf
?
function(){
return Object.setPrototypeOf({}, Array.prototype) instanceof Array;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
function(){
return Object.setPrototypeOf({}, Array.prototype) instanceof Array;
}

function "name" property

§function statements
?
function(){
function foo(){}; return foo.name === 'foo' && (function(){}).name === '';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
function(){
function foo(){}; return foo.name === 'foo' && (function(){}).name === '';
}
§function expressions
?
function(){
return (function foo(){}).name === 'foo' && (function(){}).name === '';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
function(){
return (function foo(){}).name === 'foo' && (function(){}).name === '';
}
§new Function
?
function(){
return (new Function).name === "anonymous";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
function(){
return (new Function).name === "anonymous";
}
§bound functions
?
function(){
function foo() {}; return foo.bind({}).name === "bound foo" && (function(){}).bind({}).name === "bound ";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
function foo() {}; return foo.bind({}).name === "bound foo" && (function(){}).bind({}).name === "bound ";
}
§variables (function)
?
function(){
var foo = function() {}; var bar = function baz() {}; return foo.name === "foo" && bar.name === "baz";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
No
No
function(){
var foo = function() {}; var bar = function baz() {}; return foo.name === "foo" && bar.name === "baz";
}
§object methods (function)
?
function(){
var o = { foo: function(){}, bar: function baz(){}}; o.qux = function(){}; return o.foo.name === "foo" && o.bar.name === "baz" && o.qux.name === "";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
No
No
function(){
var o = { foo: function(){}, bar: function baz(){}}; o.qux = function(){}; return o.foo.name === "foo" && o.bar.name === "baz" && o.qux.name === "";
}
§accessor properties
?
function(){
var o = { get foo(){}, set foo(x){} }; var descriptor = Object.getOwnPropertyDescriptor(o, "foo"); return descriptor.get.name === "get foo" && descriptor.set.name === "set foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
No
No
No
No
function(){
var o = { get foo(){}, set foo(x){} }; var descriptor = Object.getOwnPropertyDescriptor(o, "foo"); return descriptor.get.name === "get foo" && descriptor.set.name === "set foo";
}
§shorthand methods
?
function(){
var o = { foo(){} }; return o.foo.name === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var o = { foo(){} }; return o.foo.name === "foo";
}
§shorthand methods (no lexical binding)
?
function(){
var f = "foo"; return ({f() { return f; }}).f() === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var f = "foo"; return ({f() { return f; }}).f() === "foo";
}
§symbol-keyed methods
?
function(){
var sym1 = Symbol("foo"); var sym2 = Symbol(); var o = { [sym1]: function(){}, [sym2]: function(){} }; return o[sym1].name === "[foo]" && o[sym2].name === "";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
No
No
Error
Error
Error
Error
function(){
var sym1 = Symbol("foo"); var sym2 = Symbol(); var o = { [sym1]: function(){}, [sym2]: function(){} }; return o[sym1].name === "[foo]" && o[sym2].name === "";
}
§class statements
?
function(){
class foo {}; class bar { static name() {} }; return foo.name === "foo" && typeof bar.name === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class foo {}; class bar { static name() {} }; return foo.name === "foo" && typeof bar.name === "function";
}
§class expressions
?
function(){
return class foo {}.name === "foo" && typeof class bar { static name() {} }.name === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
return class foo {}.name === "foo" && typeof class bar { static name() {} }.name === "function";
}
§variables (class)
?
function(){
var foo = class {}; var bar = class baz {}; var qux = class { static name() {} }; return foo.name === "foo" && bar.name === "baz" && typeof qux.name === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
No
Error
Error
Error
Error
Error
Error
function(){
var foo = class {}; var bar = class baz {}; var qux = class { static name() {} }; return foo.name === "foo" && bar.name === "baz" && typeof qux.name === "function";
}
§object methods (class)
?
function(){
var o = { foo: class {}, bar: class baz {}}; o.qux = class {}; return o.foo.name === "foo" && o.bar.name === "baz" && o.qux.name === "";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
Error
No
Error
Error
Error
Error
Error
Error
function(){
var o = { foo: class {}, bar: class baz {}}; o.qux = class {}; return o.foo.name === "foo" && o.bar.name === "baz" && o.qux.name === "";
}
§class prototype methods
?
function(){
class C { foo(){} }; return (new C).foo.name === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { foo(){} }; return (new C).foo.name === "foo";
}
§class static methods
?
function(){
class C { static foo(){} }; return C.foo.name === "foo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
function(){
class C { static foo(){} }; return C.foo.name === "foo";
}
§isn't writable, is configurable
?
function(){
var descriptor = Object.getOwnPropertyDescriptor(function f(){},"name"); return descriptor.enumerable === false && descriptor.writable === false && descriptor.configurable === true;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
var descriptor = Object.getOwnPropertyDescriptor(function f(){},"name"); return descriptor.enumerable === false && descriptor.writable === false && descriptor.configurable === true;
}

String static methods

§String.raw
?
function(){
return typeof String.raw === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof String.raw === 'function';
}
§String.fromCodePoint
?
function(){
return typeof String.fromCodePoint === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
function(){
return typeof String.fromCodePoint === 'function';
}

String.prototype methods

§String.prototype.codePointAt
?
function(){
return typeof String.prototype.codePointAt === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
function(){
return typeof String.prototype.codePointAt === 'function';
}
§String.prototype.normalize
?
function(){
return typeof String.prototype.normalize === "function" && "c\u0327\u0301".normalize("NFC") === "\u1e09" && "\u1e09".normalize("NFD") === "c\u0327\u0301";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof String.prototype.normalize === "function" && "c\u0327\u0301".normalize("NFC") === "\u1e09" && "\u1e09".normalize("NFD") === "c\u0327\u0301";
}
§String.prototype.repeat
?
function(){
return typeof String.prototype.repeat === 'function' && "foo".repeat(3) === "foofoofoo";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
function(){
return typeof String.prototype.repeat === 'function' && "foo".repeat(3) === "foofoofoo";
}
§String.prototype.startsWith
?
function(){
return typeof String.prototype.startsWith === 'function' && "foobar".startsWith("foo");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
function(){
return typeof String.prototype.startsWith === 'function' && "foobar".startsWith("foo");
}
§String.prototype.startsWith throws on RegExp
?
function(){
try { "a".startsWith(/./); } catch(e) { return typeof String.prototype.startsWith === 'function'; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
function(){
try { "a".startsWith(/./); } catch(e) { return typeof String.prototype.startsWith === 'function'; }
}
§String.prototype.endsWith
?
function(){
return typeof String.prototype.endsWith === 'function' && "foobar".endsWith("bar");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
function(){
return typeof String.prototype.endsWith === 'function' && "foobar".endsWith("bar");
}
§String.prototype.endsWith throws on RegExp
?
function(){
try { "a".endsWith(/./); } catch(e) { return typeof String.prototype.endsWith === 'function'; }
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
No
Flag
No
No
function(){
try { "a".endsWith(/./); } catch(e) { return typeof String.prototype.endsWith === 'function'; }
}
§String.prototype.includes
?
function(){
return typeof String.prototype.includes === 'function' && "foobar".includes("oba");
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
No
No
No
No
function(){
return typeof String.prototype.includes === 'function' && "foobar".includes("oba");
}
§String.prototype[Symbol.iterator]
?
function(){
return typeof String.prototype[Symbol.iterator] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Error
Error
function(){
return typeof String.prototype[Symbol.iterator] === 'function';
}
§String iterator prototype chain
?
function(){
// Iterator instance var iterator = ''[Symbol.iterator](); // %StringIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Error
Error
function(){
// Iterator instance var iterator = ''[Symbol.iterator](); // %StringIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}

RegExp.prototype properties

§RegExp.prototype.flags
?
function(){
return /./igm.flags === "gim" && /./.flags === "";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
function(){
return /./igm.flags === "gim" && /./.flags === "";
}
§RegExp.prototype[Symbol.match]
?
function(){
return typeof RegExp.prototype[Symbol.match] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
return typeof RegExp.prototype[Symbol.match] === 'function';
}
§RegExp.prototype[Symbol.replace]
?
function(){
return typeof RegExp.prototype[Symbol.replace] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
return typeof RegExp.prototype[Symbol.replace] === 'function';
}
§RegExp.prototype[Symbol.split]
?
function(){
return typeof RegExp.prototype[Symbol.split] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
return typeof RegExp.prototype[Symbol.split] === 'function';
}
§RegExp.prototype[Symbol.search]
?
function(){
return typeof RegExp.prototype[Symbol.search] === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
Error
Error
function(){
return typeof RegExp.prototype[Symbol.search] === 'function';
}
§RegExp[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(RegExp, Symbol.species); return 'get' in prop && RegExp[Symbol.species] === RegExp;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Error
Flag
Error
Error
Error
Error
Error
Error
Error
Error
function(){
var prop = Object.getOwnPropertyDescriptor(RegExp, Symbol.species); return 'get' in prop && RegExp[Symbol.species] === RegExp;
}

Array static methods

§Array.from, array-like objects
?
function(){
return Array.from({ 0: "foo", 1: "bar", length: 2 }) + '' === "foo,bar";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
return Array.from({ 0: "foo", 1: "bar", length: 2 }) + '' === "foo,bar";
}
§Array.from, generator instances
?
function(){
var iterable = (function*(){ yield 1; yield 2; yield 3; }()); return Array.from(iterable) + '' === "1,2,3";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var iterable = (function*(){ yield 1; yield 2; yield 3; }()); return Array.from(iterable) + '' === "1,2,3";
}
§Array.from, generic iterables
?
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Array.from(iterable) + '' === "1,2,3";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Array.from(iterable) + '' === "1,2,3";
}
§Array.from, instances of generic iterables
?
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Array.from(Object.create(iterable)) + '' === "1,2,3";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Error
Error
Error
Error
function(){
var iterable = global.__createIterableObject([1, 2, 3]); return Array.from(Object.create(iterable)) + '' === "1,2,3";
}
§Array.from map function, array-like objects
?
function(){
return Array.from({ 0: "foo", 1: "bar", length: 2 }, function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Error
Error
Error
Error
function(){
return Array.from({ 0: "foo", 1: "bar", length: 2 }, function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1";
}
§Array.from map function, generator instances
?
function(){
var iterable = (function*(){ yield "foo"; yield "bar"; yield "bal"; }()); return Array.from(iterable, function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1,bald2";
}
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Error
Error
Error
Error
function(){
var iterable = (function*(){ yield "foo"; yield "bar"; yield "bal"; }()); return Array.from(iterable, function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1,bald2";
}
§Array.from map function, generic iterables
?
function(){
var iterable = global.__createIterableObject(["foo", "bar", "bal"]); return Array.from(iterable, function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1,bald2";
}
Yes
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Error
Error
Error
Error
function(){
var iterable = global.__createIterableObject(["foo", "bar", "bal"]); return Array.from(iterable, function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1,bald2";
}
§Array.from map function, instances of iterables
?
function(){
var iterable = global.__createIterableObject(["foo", "bar", "bal"]); return Array.from(Object.create(iterable), function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1,bald2";
}
Yes
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Error
Error
Error
Error
function(){
var iterable = global.__createIterableObject(["foo", "bar", "bal"]); return Array.from(Object.create(iterable), function(e, i) { return e + this.baz + i; }, { baz: "d" }) + '' === "food0,bard1,bald2";
}
§Array.from, iterator closing
?
function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { Array.from(iter, function() { throw 42 }); } catch(e){} return closed;
}
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function(){
var closed = false; var iter = global.__createIterableObject([1, 2, 3], { 'return': function(){ closed = true; return {}; } }); try { Array.from(iter, function() { throw 42 }); } catch(e){} return closed;
}
§Array.of
?
function(){
return typeof Array.of === 'function' && Array.of(2)[0] === 2;
}
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No
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No
function(){
return typeof Array.of === 'function' && Array.of(2)[0] === 2;
}
§Array[Symbol.species]
?
function(){
var prop = Object.getOwnPropertyDescriptor(Array, Symbol.species); return 'get' in prop && Array[Symbol.species] === Array;
}
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Error
Flag
Error
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Error
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Error
Error
Error
function(){
var prop = Object.getOwnPropertyDescriptor(Array, Symbol.species); return 'get' in prop && Array[Symbol.species] === Array;
}

Array.prototype methods

§Array.prototype.copyWithin
?
function(){
return typeof Array.prototype.copyWithin === 'function';
}
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No
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No
function(){
return typeof Array.prototype.copyWithin === 'function';
}
§Array.prototype.find
?
function(){
return typeof Array.prototype.find === 'function';
}
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No
Flag
No
No
function(){
return typeof Array.prototype.find === 'function';
}
§Array.prototype.findIndex
?
function(){
return typeof Array.prototype.findIndex === 'function';
}
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Flag
No
No
function(){
return typeof Array.prototype.findIndex === 'function';
}
§Array.prototype.fill
?
function(){
return typeof Array.prototype.fill === 'function';
}
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Flag
No
No
function(){
return typeof Array.prototype.fill === 'function';
}
§Array.prototype.keys
?
function(){
return typeof Array.prototype.keys === 'function';
}
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No
No
function(){
return typeof Array.prototype.keys === 'function';
}
§Array.prototype.values
?
function(){
return typeof Array.prototype.values === 'function';
}
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function(){
return typeof Array.prototype.values === 'function';
}
§Array.prototype.entries
?
function(){
return typeof Array.prototype.entries === 'function';
}
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No
function(){
return typeof Array.prototype.entries === 'function';
}
§Array.prototype.splice
?
function(){
if ([0, 1, 2].splice(0).length !== 3) { // IE <= 8 and other pre-ES6 engines fail this check return false; } var a = [1, 2]; var result = a.splice(); if (a.length !== 2 || result.length !== 0) { // Safari 5.0 has this bug return false; } var obj = {}; Array.prototype.splice.call(obj, 0, 0, 1); if (obj.length !== 1) { return false; } var spliceWorksWithLargeSparseArrays = (function () { // Per https://github.com/es-shims/es5-shim/issues/295 // Safari 7/8 breaks with sparse arrays of size 1e5 or greater var arr = new Array(1e5); // note: the index MUST be 8 or larger or the test will false pass arr[8] = 'x'; arr.splice(1, 1); for (var i = 0; i < arr.length; i += 1) { if (arr[i] === 'x') { return i === 7; } } return false; }()); var spliceWorksWithSmallSparseArrays = (function () { // Per https://github.com/es-shims/es5-shim/issues/295 // Opera 12.15 breaks on this, no idea why. var n = 256; var arr = []; arr[n] = 'a'; arr.splice(n + 1, 0, 'b'); return arr[n] === 'a'; }()); return spliceWorksWithLargeSparseArrays && spliceWorksWithSmallSparseArrays;
}
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function(){
if ([0, 1, 2].splice(0).length !== 3) { // IE <= 8 and other pre-ES6 engines fail this check return false; } var a = [1, 2]; var result = a.splice(); if (a.length !== 2 || result.length !== 0) { // Safari 5.0 has this bug return false; } var obj = {}; Array.prototype.splice.call(obj, 0, 0, 1); if (obj.length !== 1) { return false; } var spliceWorksWithLargeSparseArrays = (function () { // Per https://github.com/es-shims/es5-shim/issues/295 // Safari 7/8 breaks with sparse arrays of size 1e5 or greater var arr = new Array(1e5); // note: the index MUST be 8 or larger or the test will false pass arr[8] = 'x'; arr.splice(1, 1); for (var i = 0; i < arr.length; i += 1) { if (arr[i] === 'x') { return i === 7; } } return false; }()); var spliceWorksWithSmallSparseArrays = (function () { // Per https://github.com/es-shims/es5-shim/issues/295 // Opera 12.15 breaks on this, no idea why. var n = 256; var arr = []; arr[n] = 'a'; arr.splice(n + 1, 0, 'b'); return arr[n] === 'a'; }()); return spliceWorksWithLargeSparseArrays && spliceWorksWithSmallSparseArrays;
}
§Array.prototype[Symbol.iterator]
?
function(){
return typeof Array.prototype[Symbol.iterator] === 'function';
}
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Error
Error
function(){
return typeof Array.prototype[Symbol.iterator] === 'function';
}
§Array iterator prototype chain
?
function(){
// Iterator instance var iterator = [][Symbol.iterator](); // %ArrayIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
Yes
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Error
Error
function(){
// Iterator instance var iterator = [][Symbol.iterator](); // %ArrayIteratorPrototype% var proto1 = Object.getPrototypeOf(iterator); // %IteratorPrototype% var proto2 = Object.getPrototypeOf(proto1); return proto2.hasOwnProperty(Symbol.iterator) && !proto1 .hasOwnProperty(Symbol.iterator) && !iterator .hasOwnProperty(Symbol.iterator) && iterator[Symbol.iterator]() === iterator;
}
§Array.prototype[Symbol.unscopables]
?
function(){
var unscopables = Array.prototype[Symbol.unscopables]; if (!unscopables) { return false; } var ns = "find,findIndex,fill,copyWithin,entries,keys,values".split(","); for (var i = 0; i < ns.length; i++) { if (Array.prototype[ns[i]] && !unscopables[ns[i]]) return false; } return true;
}
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Error
Error
function(){
var unscopables = Array.prototype[Symbol.unscopables]; if (!unscopables) { return false; } var ns = "find,findIndex,fill,copyWithin,entries,keys,values".split(","); for (var i = 0; i < ns.length; i++) { if (Array.prototype[ns[i]] && !unscopables[ns[i]]) return false; } return true;
}

Number properties

§Number.isFinite
?
function(){
return typeof Number.isFinite === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
function(){
return typeof Number.isFinite === 'function';
}
§Number.isInteger
?
function(){
return typeof Number.isInteger === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Number.isInteger === 'function';
}
§Number.isSafeInteger
?
function(){
return typeof Number.isSafeInteger === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Number.isSafeInteger === 'function';
}
§Number.isNaN
?
function(){
return typeof Number.isNaN === 'function';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
function(){
return typeof Number.isNaN === 'function';
}
§Number.parseFloat
?
function(){
var actualGlobal = Function('return this')(); return typeof Number.parseFloat === 'function' && Number.parseFloat === actualGlobal.parseFloat;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
var actualGlobal = Function('return this')(); return typeof Number.parseFloat === 'function' && Number.parseFloat === actualGlobal.parseFloat;
}
§Number.parseInt
?
function(){
var actualGlobal = Function('return this')(); return typeof Number.parseInt === 'function' && Number.parseInt === actualGlobal.parseInt;
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
var actualGlobal = Function('return this')(); return typeof Number.parseInt === 'function' && Number.parseInt === actualGlobal.parseInt;
}
§Number.EPSILON
?
function(){
return typeof Number.EPSILON === 'number';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Number.EPSILON === 'number';
}
§Number.MIN_SAFE_INTEGER
?
function(){
return typeof Number.MIN_SAFE_INTEGER === 'number';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Number.MIN_SAFE_INTEGER === 'number';
}
§Number.MAX_SAFE_INTEGER
?
function(){
return typeof Number.MAX_SAFE_INTEGER === 'number';
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Number.MAX_SAFE_INTEGER === 'number';
}

Math methods

§Math.clz32
?
function(){
return typeof Math.clz32 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.clz32 === "function";
}
§Math.imul
?
function(){
return typeof Math.imul === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.imul === "function";
}
§Math.sign
?
function(){
return typeof Math.sign === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.sign === "function";
}
§Math.log10
?
function(){
return typeof Math.log10 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.log10 === "function";
}
§Math.log2
?
function(){
return typeof Math.log2 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.log2 === "function";
}
§Math.log1p
?
function(){
return typeof Math.log1p === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.log1p === "function";
}
§Math.expm1
?
function(){
return typeof Math.expm1 === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.expm1 === "function";
}
§Math.cosh
?
function(){
return typeof Math.cosh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.cosh === "function";
}
§Math.sinh
?
function(){
return typeof Math.sinh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.sinh === "function";
}
§Math.tanh
?
function(){
return typeof Math.tanh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.tanh === "function";
}
§Math.acosh
?
function(){
return typeof Math.acosh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.acosh === "function";
}
§Math.asinh
?
function(){
return typeof Math.asinh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
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Yes
Yes
Yes
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Yes
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Yes
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Yes
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No
No
function(){
return typeof Math.asinh === "function";
}
§Math.atanh
?
function(){
return typeof Math.atanh === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.atanh === "function";
}
§Math.trunc
?
function(){
return typeof Math.trunc === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
function(){
return typeof Math.trunc === "function";
}
§Math.fround
?
function(){
return typeof Math.fround === "function";
}
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes