调用函数与参数数组

问题描述

我可以打电话与参数数组的函数在JavaScript的一个便捷的方式？

Can I call a function with array of arguments in a convenient way in JavaScript?

例如：

var fn = function() {
    console.log(arguments);
}

var args = [1,2,3];

fn(args);

我需要参数是 [1,2,3] ，就像我的数组。

推荐答案

您应该使用<$c$c>apply:

var fn = function() {
    console.log(arguments);
};

var args = [1,2,3];

fn.apply(null, args);

应用将使相当于函数调用：

Apply will make the equivalent function call:

fn(1,2,3);

请注意，我用空为适用，将设置这个关键字全局对象（窗口）内 FN 。

Notice that I used null as the first argument of apply, that will set the this keyword to the global object (window) inside fn.

您也应该知道，在<$c$c>arguments对象是不是一个真正的数组，这是一个类似数组的对象，包含对应于被用来调用你的函数，这给你一个长度属性参数数值索引参数的数目使用，而<$c$c>arguments.callee属性，是对执行的函数的引用（匿名函数的递归有用）。

Also you should know that the arguments object is not really an array, it's an array-like object, that contains numeric indexes corresponding to the arguments that were used to call your function, a length property that gives you the number of arguments used, and the arguments.callee property that is a reference to the executing function (useful for recursion on anonymous functions).

如果您想从论据是一个数组对象，你可以使用 Array.prototype.slice 方法：

If you want to make an array from your arguments object, you can use the Array.prototype.slice method:

var fn = function() {
  var args = Array.prototype.slice.call(arguments);
  console.log(args);
};

编辑：在回答您的意见，是的，你可以使用移方法，并将其返回值作为上下文（这个关键字）：

In response to your comment, yes, you could use the shift method and set its returned value as the context (the this keyword) on your function:

fn.apply(args.shift(), args);

但请记住，移将从原来的数组中删除第一个元素，你的功能将不首先参数调用。

But remember that shift will remove the first element from the original array, and your function will be called without that first argument.

如果你仍然需要调用你的函数与所有其他参数，您可以：

If you still need to call your function with all your other arguments you can:

fn.apply(args[0], args);

如果你不想改变的背景下，你可以简单地提取您的函数中的第一个参数：

And if you don't want to change the context, you could simply extract the first argument inside your function:

var fn = function() {
  var args = Array.prototype.slice.call(arguments),
      firstArg = args.shift();

  console.log(args, firstArg);
};

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