为什么箭头函数没有参数数组? [英] Why do arrow functions not have the arguments array?

问题描述

function foo(x) {
   console.log(arguments)
} //foo(1) prints [1]

但是

var bar = x => console.log(arguments) 

以相同方式调用时会出现以下错误:

gives the following error when invoked in the same way:

Uncaught ReferenceError: arguments is not defined

推荐答案

箭头函数没有这个，因为 arguments 类数组对象是一种解决方法，ES6 已经解决了这个问题rest 参数:

Arrow functions don't have this since the arguments array-like object was a workaround to begin with, which ES6 has solved with a rest parameter:

var bar = (...arguments) => console.log(arguments);

arguments 在这里绝不是保留的，而是被选择的.您可以随心所欲地调用它，也可以将其与普通参数结合使用:

arguments is by no means reserved here but just chosen. You can call it whatever you'd like and it can be combined with normal parameters:

var test = (one, two, ...rest) => [one, two, rest];

你甚至可以走另一条路，如这个奇特的应用所示:

You can even go the other way, illustrated by this fancy apply:

var fapply = (fun, args) => fun(...args);

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