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) |