This chapter contains information about JavaScript's version history and implementation status for Mozilla/SpiderMonkey-based JavaScript applications, such as Firefox.
Learn more about the ECMAScript standards on which the JavaScript language is based on.
Implementation status for the current standard ECMA-262 Edition 5.1 in Mozilla-based engines and products.
Implementation status for the draft ECMA-262 Edition 6 (ES2015) in Mozilla-based engines and products.
Implementation status for upcoming ECMA-262 features as per the yearly (ES2016/ES2017/ES2018/...) release schedule in Mozilla-based engines and products.
弃用 ( ). The explicit versioning and opt-in of language features was Mozilla-specific and are in process of being removed . Firefox 4 was the last version which referred to a JavaScript version (1.8.5). With new ECMA standards, JavaScript language features are now often mentioned with their initial definition in ECMA-262 Editions such as ECMAScript 2015.
JavaScript was released as version 1.0 in March 1996 in Netscape Navigator 2.0 and Internet Explorer 2.0.
Version shipped in Netscape Navigator 3.0. Released on August 19, 1996.
Version shipped in Netscape Navigator 4.0-4.05. Released on June 11, 1997.
Version shipped with Netscape's server-side JavaScript. Released in 1999.
Array
methods plus
String
and
Array
generics.
let
expressions, and destructuring assignment.
Array.reduce()