The arguments.length
property contains the number of arguments passed to the function.
Syntax
arguments.length
Description
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
).
Examples
Using 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
Specifications
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 |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |