arguments.length - JavaScript 编辑

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 (ECMA-262) Arguments Exotic Objects	Living Standard

浏览器支持

BCD tables only load in the browser

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.

相关链接

• Function.length