为什么不能重命名console.log? [英] Why can't I rename console.log?

问题描述

这似乎应该很简单:

var print = console.log;
print("something"); // Fails with Invalid Calling Object (IE) / Invalid Invocation (Chrome)

为什么不起作用?

推荐答案

如果您使用全局对象作为接收方来调用该方法，而该方法严格地是非泛型的，并且恰好需要 Console的实例作为接收者.

Becase you are calling the method with the global object as the receiver while the method is strictly non-generic and requires exactly an instance of Console as the receiver.

通用方法的一个示例是 Array.prototype.push :

An example of generic method is Array.prototype.push:

   var print = Array.prototype.push;
   print(3);
   console.log(window[0]) // 3

您可以执行以下操作:

var print = function() {
     return console.log.apply( console, arguments );
};

ES5提供了 .bind ，它也实现了与上述相同的功能:

And ES5 provides .bind that also achieves the same as above:

var print = console.log.bind( console );

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