On the standards track: Yes
Is Experimental: No
Is Deprecated: No
In Bun version 1.0.0 on 2023-09-08
In Chrome version 49 on 2016-03-02
In Chrome Android version 49 on 2016-03-09
In Deno version 1.0 on 2020-05-13
In Edge version 12 on 2015-07-29
In Firefox version 18 on 2013-01-08 Note: In Firefox 42, the implementation got updated to reflect the final ES2015 specification: The result is now checked if it is an array and if the array elements are either of type string or of type symbol. Enumerating duplicate own property names is not a failure anymore.
In Firefox for Android version 18 on 2013-01-08 Note: In Firefox for Android 42, the implementation got updated to reflect the final ES2015 specification: The result is now checked if it is an array and if the array elements are either of type string or of type symbol. Enumerating duplicate own property names is not a failure anymore.
Not in Internet Explorer
In Node.js version 6.0.0 on 2016-04-26
In Quest Browser version 5.0 on undefined
In Opera version 36 on 2016-03-15
In Opera Android version 36 on 2016-03-31
In Safari version 10 on 2016-09-20
In Safari on iOS version 10 on 2016-09-13
In Samsung Internet version 5.0 on 2016-12-15
In WebView Android version 49 on 2016-03-09
In WebView on iOS version 10 on 2016-09-13