继承

1. 原型链

Child.prototype = new Father();
Child.prototype.constructor = Child;

2. 构造函数

Father.call(Child);

3. 组合

Father.call(Child);
Child.prototype = new Father();
Child.prototype.constructor = Child;

4. 探索

Father.call(Child);
Child.prototype = Father.prototype;
Child.prototype.constructor = Child;

5. 成功

• 使用 Object.create

Father.call(Child);
Child.prototype = Object.create(Father.prototype)//以Father.prototype对象为原型，生成了Child.prototype对象
Child.prototype.constructor = Child;

• 不使用

(function () {
    // 创建一个没有实例方法的类
    var Super = function () { };
    Super.prototype = Father.prototype;
    //将实例作为子类的原型
    Child.prototype = new Super();
    Child.prototype.constructor = Child;
})();

6. 升级Class