New in JavaScript

Este capítulo contém informações sobre o histórico de versões do Javascript e situação de implementações de aplicações Mozilla/SpiderMonkey baseadas em Javascript, como o Firefox.

Versões ECMAScript

Recursos da Linguagem

Saiba mais sobre os padrões ECMAScript em que o Javascript é baseado.

Suporte ECMAScript 5

Status da implementação para o padrão atual ECMA-262 Edition 5.1 em engines Mozilla-based e produtos.

Suporte a ECMAScript 6

Status da implementação para o rascunho de ECMA-262 Edition 6 in em engines Mozilla-based e produtos.

Suporte a ECMAScript 7

Status da implementação para o padrão ECMA-262 Edition 7 que virá em engines Mozilla-based e produtos.

Notas de distribuição JavaScript

Firefox JavaScript changelog

Veja esse changelog para características de JavaScript implementadas no Firefox 5 e posteriormente.

Chrome JavaScript changelog

(TODO). Vem esse changelog para características de JavaScript implementas nas distribuições do Chrome.

JavaScript versions

Deprecated ( ). The explicit versioning and opt-in of language features was Mozilla-specific and is in process of being removed. Firefox 4 was the last version which referred to an 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 Edition 6 (ES6).

JavaScript was released as version 1.0 in March 1996 in Netscape Navigator 2.0 and Internet Explorer 2.0.

JavaScript 1.1

Version shipped in Netscape Navigator 3.0. Released on August 19, 1996.

JavaScript 1.2

Version shipped in Netscape Navigator 4.0-4.05. Released on June 11, 1997.

JavaScript 1.3

Version shipped in Netscape Navigator 4.06-4.7x. Released on October 19, 1998.
Standardization work to be compliant with ECMA-262 1st and 2nd Edition.

JavaScript 1.4

Version shipped in Netscape's server side JavaScript. Released in 1999.

JavaScript 1.5

Version shipped in Netscape Navigator 6.0 and Firefox 1.0. Release on November 14, 2000.
Standardization work to be compliant with ECMA-262 3rd Edition.

JavaScript 1.6

Version shipped in Firefox 1.5. Released in November 2005.
Includes ECMAScript for XML (E4X), new Array methods plus String and Array generics.

JavaScript 1.7

Version shipped in Firefox 2. Released in October 2006.
Includes generators, iterators, array comprehensions, let expressions, and destructuring assignment.

JavaScript 1.8

Version shipped in Firefox 3. Released in June 2008.
Includes expression closures, generator expressions and Array.reduce()

JavaScript 1.8.1

Version shipped in Firefox 3.5. Released on June 30, 2009.
Includes the TraceMonkey JIT and supports native JSON.

JavaScript 1.8.2

Version shipped in Firefox 3.6. Released June 22, 2009.
Includes only minor changes.

JavaScript 1.8.5

Version shipped in Firefox 4. Released July 27, 2010.
Includes many new features for ECMA-262 Edition 5 compliance.
This is the last JavaScript version.

Features still requiring version opt-in

let statement

The let statement requires the JavaScript version 1.7 (or higher) opt-in. See bug 932517 and bug 932517.