在JavaScript中更改构造函数 [英] Changing constructor in JavaScript

问题描述

我正在尝试一段时间来切换对象的构造函数而我失败了。继续代码将显示我需要的示例。谢谢。

I am trying for a while to switch constructor for a object and I am failing. Continuing code will show example of what I need. Thanks.

    <script type="text/javascript">

    function Me(){

      this.name = "Dejan";
    }

    function You(){

        this.name = "Ivan";
    }


    Me.prototype.constructor = You;
    somebody = new Me();


    alert(somebody.name); // **It gives Dejan, and I am expecting Ivan**

    </script>

推荐答案

您无法更改对象的构造函数，然而，您可以更改构造函数返回的对象的类型，如（在您的示例中）

You can't change the constructors of an object, you can however change the 'type' of the object the constructor returns, with (as in your example)

Me.prototype = new You();

这将导致新的Me（）从对象You继承。然而，Me（）函数中的this.name将掩盖从你继承的那个，所以做这样的事情：

which would cause new Me()'s to inherit from the object You. However this.name in the Me() function will overshadow the one inherited from you so do something like this:

function Me(){
    this.name =  this.name || "Dejan";
}
function You(){
    this.name = this.name || "Ivan";
}
Me.prototype = new You();
somebody = new Me();
alert(somebody.name); 

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