为什么重新分配Object.prototype不起作用? [英] Why is reassigning Object.prototype not working?

问题描述

为什么这不起作用?

// this one works as I expected, when objSayHello()
Object.prototype.objSayHello = function(){alert('Hello,from OBJECT prototype')};
// NOT working !
Object.prototype ={objSayHello: function(){alert('Hello,from OBJECT prototype')}};

objSayHello();

推荐答案

1. 因为您已经替换了Object原型，所以您要将objSayHello方法添加到任何从Object派生的对象(所有对象).

1. Because you've replaced the Object prototype, so you're adding a objSayHello method to any object descending from Object (all objects).

请勿替换Object.prototype.

您可能想要的是:

someObj.prototype.objSayHello = function(){alert('Hello,from OBJECT prototype')};

然后通过以下方式调用它:

Then to call it with:

someObj.objSayHello();

您似乎打算做的是:

Object.prototype.objSayHello = function(){alert('Hello,from OBJECT prototype')};

但这可能不是一个好主意，因为如果处理不正确，它将与迭代器(for...in)冲突.

But that is probably a bad idea as it will conflict with iterators (for...in) if not handled correctly.

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