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

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung InternetNode.js
Basic supportChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes

Legend

Full support  
Full support

相关链接

文档标签和贡献者

此页面的贡献者: fscholz, teoli, ziyunfei
最后编辑者: fscholz,