← Back to index

JavaScript

Created: 2015-03-23 19:02  |  Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript

JavaScript

JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but used in many non-browser environments as well such as node.js or Apache CouchDB. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles. Read more about JavaScript.

The JavaScript standard is ECMAScript. As of 2012, all modern browsers fully support ECMAScript 5.1. Older browsers support at least ECMAScript 3. A 6th major revision of the standard is in the works and is expected to be finished around mid 2015.

This section of the site is dedicated to the JavaScript language itself, the parts that are not specific to Web pages, or other host environments. For information about APIs specific to Web pages, please see Web APIs and DOM.

JavaScript is not to be confused with the Java programming language. Java is a trademark or registered trademark of Oracle in the U.S. and other countries.

Tutorials

Learn how to program with JavaScript.

Introductory

JavaScript Guide
If you are new to JavaScript, this guide will walk you through the language.
JavaScript technologies overview
Introduction to the web browser JavaScript landscape.
Introduction to Object Oriented JavaScript
Introduction to the concepts of object oriented programming in JavaScript.

Intermediate

A re-introduction to JavaScript
An overview for those who think they know about JavaScript.
JavaScript data structures
Overview of available data structures in JavaScript.
Equality comparisons and when to use them
JavaScript provides three different value-comparison operations: strict equality using === and loose equality using ==.

Advanced

Inheritance and the prototype chain
Explanation of the widely misunderstood and under-estimated prototype-based inheritance.
Strict mode
A restricted variant of JavaScript.
JavaScript typed arrays
JavaScript typed arrays provide a mechanism for accessing raw binary data.
Memory Management
Memory life cycle and garbage collection in JavaScript.

Reference

Browse the complete JS reference documentation.

Standard objects
Get to know standard built-in objects Array, Boolean, Date, Error, Function, JSON, Math, Number, Object, RegExp, String, Map, Set, WeakMap, WeakSet, and others.
Expressions & operators
Learn more about the behavior of JavaScript's operators instanceof, typeof, new, this, and more.
Statements & declarations
Learn how do-while, for-in, for-of, try-catch, let, var, const, if-else, switch, and more JavaScript statements and keywords work.
Functions
Learn how to work with JS functions to develop your applications.

Tools & resources

Helpful tools while writing and debugging your JavaScript code.

Firefox Developer Tools
Scratchpad, Web Console, JavaScript Profiler, Debugger, and more.
Firebug
Edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.
JavaScript Shells
A JavaScript shell allows you to quickly test snippets of JavaScript code.
TogetherJS

Collaboration made easy.

Stack Overflow
Stack Overflow questions tagged with "JavaScript".
JavaScript versions and release notes
Browse JavaScript's feature history and implementation status.

Join the JavaScript community