本次函数调用时传入函数的实参数量.
Syntax
arguments.length
描述
arguments.length表示的是实际上向函数传入了多少个参数,这个数字可以比形参数量大,也可以比形参数量小(形参数量的值可以通过Function.length获取到).
例子
例子: 使用arguments.length
这个例中,我们定义了一个可以相加任意个数字的函数.
function adder(base, /*, n2, ... */) { base = Number(base); for (var i = 0; i < arguments.length; i++) { base += Number(arguments[i]); } return base; }
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 1st Edition (ECMA-262) | Standard | Initial definition. Implemented in JavaScript 1.1 |
ECMAScript 5.1 (ECMA-262) Arguments Object |
Standard | |
ECMAScript 2015 (6th Edition, ECMA-262) Arguments Exotic Objects |
Standard | |
ECMAScript Latest Draft (ECMA-262) Arguments Exotic Objects |
Draft |
浏览器支持
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out
https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | Server | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
length |
Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE Full support 4 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support 1.0 | nodejs Full support Yes |
Legend
- Full support
- Full support