Javascript继承和方法覆盖 [英] Javascript inheritance and method overriding

问题描述

假设我有这样一个类：

function Widget() {
    this.id = new Date().getTime();
    // other fields
}
Widget.prototype = {
    load: function(args) {
        // do something
    }
}

从这个类我创建了一些继承相同原型但有一些添加方法的其他类。我想要做的是能够在子类中定义一个load（）方法，该方法首先调用父方法，然后执行一些代码。类似于：

From this class I created some other classes which inherit the same prototype but have some added methods. What I want to do is being able to define a load() method in the sub-classes which first calls the parent method and then execute some code. Something like:

SpecialWidget.prototype = {
    load: function(args) {
        super.load(args);
        // specific code here
    }
}

我知道Javascript中没有超级关键字，但必须有办法做到这一点。

I know there's no super keyword in Javascript but there must be a way to do this.

推荐答案

你可以像这样模拟：

SpecialWidget.prototype = {
    load: function(args) {
        Widget.prototype.load.call(this, args);
        // specific code here
    }
}

或者你可以像这样创建自己的超级属性：

Or you can create your own super property like this:

SpecialWidget.prototype.parent = Widget.prototype;

SpecialWidget.prototype = {
    load: function(args) {
        this.parent.load.call(this,args);
        // specific code here
    }
}

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