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Mozilla对ECMAScript 6的支持


ECMAScript 2015 (6th Edition)是目前ECMAScript语言规范的标准。通常被称为"ES6",在SpiderMonkey 中它规定了JavaScript的实现标准, SpiderMonkey是一个JavaScript引擎,被广泛在火狐浏览器等谋智的众多产品中。

Code-named "" or "Harmony", the first working draft (based on ECMAScript 5.1) was published on July 12, 2011 as "". In August 2014, the ECMAScript 6 draft specification was feature frozen and went through a stabilization and bug fixing period. Finally, ECMA-262 Edition 6 got officially approved and published as a standard on June 17, 2015 by the ECMA General Assembly. It will also appear as the international industry standard ISO/IEC 16262:2016.

A PDF and HTML version of the standard can be freely downloaded on

A channel for feedback on ECMAScript standards is es-discuss.

Firefox 已经支持的 ECMAScript 6 特性

这里列出的功能已经在Firefox中支持;the version in which support was added is also indicated for each feature.


Additions to the Array object



Additions to the Number object

Additions to the Object object

Additions to the Date object



Additions to the RegExp object

Additions to the String object


Typed Arrays

Typed arrays are specified as part of ECMAScript 6 and no longer in their own specification.






The following features are (partially) implemented in Firefox, but are not compliant with the specification. There are a couple of possible reasons for this: Firefox's implementation is based on an older draft of the ES6 specification, or Firefox's current implementation is an experimental design added before a similar feature was added to the ES6 specification.

Features partially supported by Firefox

These features, while part of ECMAScript 6, are only partially implemented in Firefox, and are only available in nightly builds.

New class syntax

Firefox还未支持的 ECMAScript 6 特性

The following features are part of the ECMAScript 6 specification, but haven't been implemented yet in Firefox. The bug tracking implementation of the feature is noted for each.



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