ECMAScript 6 implementation tests

Test directly in each browser the implementation of the new features of the language.

The choice of features is based on the implementation in at least one browser (Firefox actually). Then we can see through these tests when other browsers are implementing and so when they can be used in production.

This page concerns the JavaScript language but a similar page is dedicated to test the implementation of HTML 5 across browsers.

	Added to JavaScript	Implemented?
Syntax	Const (ES6)
	Scoping. Reserved word let (1.7)
	Destructuring assignment: [a , b ] = [x , y] (1.7)
	Async/await
	ArrayBuffer and typed arrays, Int32Array, etc... (ES6)
Array	Method reduce of Array (1.8)
	Method filter of Array (1.6)
	Method map of Array (1.6)
	Methods every and some of Array (1.6)
	Methods indexOf and lastIndexOf of Array (1.6)
Object	Object.keys() (1.8.5)
	Object.entries() (ES2017)
String	String.trim() (1.8.1)
New objects	Object Set and method has, attribute size (ES6)
	Object Map and methods set, get, attribute size (ES6)
	Object JSON (1.5)
	Promise (TC39)
	Proxy (ES6)
	Iterator (1.7)
	Generator. Reserved word yield (1.7)
API	Fetch

ES6 is a shortcut to ECMAScript version 6.

More details about new methods of Array. Another page on the site is dedicated to Harmony.

If you want to know what Microsoft intends to implement or not in Edge (and what is in progress), see the Platform Status.
The indications for other browsers are not always updated.