f（arguments）与f.apply（this，arguments）之间的区别是什么？ [英] What's the difference between f(arguments) to f.apply(this,arguments)?

问题描述

我很久没学过JavaScript了，现在我正在尝试实现Decorator模式：

I have not been studying JavaScript for a long time and now I'm trying to implement the Decorator pattern:

function wrap(f, before, after){
        return function(){
            return before + f(arguments) + after;
        }
}

我想知道的是，如果我们更换 f（参数）到 f.apply（this，arguments）输出没有明显差异。
你能否澄清哪个案例更可取？为什么？

What I'm wondering about is that if we replace f(arguments) to f.apply(this,arguments) there is no obvious difference in output. Could you please clarify which case is preferable and why?

UPD：
我想我已经理解了什么是瓶颈:)
如果我们用上述代码装饰函数而没有参数，一切都会好的。但是如果我们有参数，我们将不得不枚举它们，如 arguments [0]，arguments [1] 等。我是对的吗？

推荐答案

1. f（参数）只需调用 f 并传递一个类似 Array 的对象（包含参数），这是不你想要的。

1. f(arguments) just calls f and passes an Array-like object (containing arguments) to it, this is not what you'd want.

f.call（this，arguments [0]，arguments [1]，..）会要求你列出每个参数都出来，它与 f（arguments [0]，arguments [1]，..）几乎相同，减去函数上下文。

f.call(this, arguments[0], arguments[1], ..) would require you to list every argument out and it's pretty much the same as f(arguments[0], arguments[1], ..), minus the function context.

f.apply（this，arguments）将调用 f 并且将 arguments 中的每个参数作为实际参数传递。

f.apply(this, arguments) would call f and passes each argument in arguments as actual arguments.

方法如果你想要实现一个包装器函数而不必考虑传递给 f 的参数，你会想要＃3。

Method #3 is what you'd want if you're trying to implement a wrapper function and not have to consider what arguments are being passed into f.

了解有关函数方法的更多信息：

Learn more about methods for Function:

• call（）： https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/致电


• apply（）： https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/apply


• arguments ： https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/arguments

• call(): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/call
• apply(): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/apply
• arguments: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/arguments

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