The arguments.length
property contains the number of arguments passed to the function.
arguments.length
The arguments.length property provides the number of arguments actually passed to a function. This can be more or less than the defined parameter's count (see Function.length
).
arguments.length
In this example we define a function that can add two or more numbers together.
function adder(base /*, n2, ... */) { base = Number(base); for (var i = 1; i < arguments.length; i++) { base += Number(arguments[i]); } return base; }
Note the difference between Function.length
and arguments.length
Specification | Status | Comment |
---|---|---|
ECMAScript 1st Edition (ECMA-262) | Standard | Initial definition. Implemented in JavaScript 1.1 |
ECMAScript 5.1 (ECMA-262) The definition of 'Arguments Object' in that specification. | Standard | |
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Arguments Exotic Objects' in that specification. | Standard | |
ECMAScript Latest Draft (ECMA-262) The definition of 'Arguments Exotic Objects' in that specification. | Living Standard |
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | Yes | Yes | Yes | Yes | Yes | Yes |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/arguments/length