Javascript - 扩展对象时出错

Question

我的代码如下:

function Example(){}
Example.myMethod = function(){};
function SpecificExample(){}
SpecificExample.prototype = Object.create(Example.prototype);
SpecificExample.prototype.constructor = SpecificExample;

我想要 SpecificExample 扩展 Example。为什么这段代码不起作用？

Answer 1

Example.myMethod 是附加到构造函数/对象的函数，但它不是其原型(prototype)的一部分。这可以称为静态函数(在 ES6 中就是这样)。要使它们成为原型(prototype)的一部分，请将它们添加到原型(prototype)本身:

function Example(){}
Example.prototype.myMethod = function(){};
function SpecificExample(){}
SpecificExample.prototype = Object.create(Example.prototype);
// As @JaredSmith said, you shouldn't change the constructor, and why would you?
// function SpecificExample(){} IS your constructor. So...
// SpecificExample.prototype.constructor = SpecificExample;
// should simply be removed.