我想克隆一个 javascript 类。将方法添加到克隆属性而不实际覆盖现有方法？答案

【问题标题】：I want to clone a javascript class. add methods to the cloned property without actually overwriting the exisiting methods?我想克隆一个 javascript 类。将方法添加到克隆属性而不实际覆盖现有方法？
【发布时间】：2012-05-16 21:28:48
【问题描述】：

我正在尝试将方法添加到克隆的原型类属性。我已经粘贴了下面的代码。

当我向这个 sn-p 代码添加方法时，它会覆盖超类中定义的内容。

<script src="http://ajax.googleapis.com/ajax/libs/prototype/1.6.0.3/prototype.js" type="text/javascript"></script>
<script type="text/javascript">
var Animal = Class.create({
    initialize: function(name, sound) {
    this.name  = name;
    this.sound = sound;
    },

    speak: function() {
    alert(this.name + " says: " + this.sound + "!");
    }
});

Animal.movement = {
    move: function(direction){
        alert('moving: ' + direction)
    }
}

var AnimalClone = { }
Object.extend(AnimalClone, Animal);

//Now i want to add 'jump' to this list of methods 
//without over writing the inherited 'move' method
AnimalClone.movement = {
    jump: function(height){
        alert('jumped:' + height)
    }
}
</script>

【问题讨论】：

标签： javascript oop inheritance prototypejs

【解决方案1】：

由于movement 是一个对象，您还必须通过使用原型访问它来扩展它

var Animal = Class.create({
    initialize: function(name, sound) {
        this.name = name;
        this.sound = sound;
    },
    movement: {
        move: function(direction) {
            alert('moving: ' + direction);
        }
    }
});

var AnimalClone = Class.create({});
AnimalClone.prototype = Object.extend(new Animal(),{});

AnimalClone.prototype.movement = Object.extend(AnimalClone.prototype.movement, {
        jump: function(height) {
            alert('jumped:' + height);
        }
});

var animalClone = new AnimalClone;
animalClone.movement.move("up");
animalClone.movement.jump("10mts");

【讨论】：

【解决方案2】：

您需要扩展 movement 对象，而不是覆盖它：

Object.extend(AnimalClone.movement, {
    jump: function(height){
        alert('jumped:' + height)
    }
});

【讨论】：