JavaScript reference - JavaScript | MDN

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The JavaScript reference serves as a repository of facts about the JavaScript language. The entire language is described here in detail. As you write JavaScript code, you'll refer to these pages often (thus the title "JavaScript reference").
The JavaScript language is intended to be used within some larger environment, be it a browser, server-side scripts, or similar. For the most part, this reference attempts to be environment-agnostic and does not target a web browser environment.
If you are new to JavaScript, start with the guide. Once you have a firm grasp of the fundamentals, you can use the reference to get more details on individual objects and language constructs.
JavaScript standard built-in objects, along with their methods and properties.
JavaScript statements and declarations
JavaScript expressions and operators.
JavaScript functions.
JavaScript regular expressions.
This page was last modified on Sep 15, 2026 by MDN contributors.
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