javascript的几种继承

function Parent(){
        this.name=‘mike‘;
    }
    function Child(){
        this.age=12;
    }
    //儿子继承父亲（原型链）
    Child.prototype=new Parent();//Child继承Parent，通过原型形成链条
    var test=new Child();
    console.log(test.age);
    console.log(test.name);//得到被继承的属性
    //孙子继续原型链继承儿子
    function Brother(){
        this.weight=60;
    }
    Brother.prototype=new Child();//继承原型链继承
    var brother=new Brother();
    console.log(brother.name);//继承了Parent和Child，弹出mike
    console.log(brother.age);//12

    console.log(brother instanceof Child);//ture
    console.log(brother instanceof Parent);//ture
    console.log(brother instanceof Object);//ture

function Parent(age){
        this.name=[‘mike‘,‘jack‘,‘smith‘];
        this.age=age;
    }
    function Child(age){
        Parent.call(this,age);//把this指向Parent,同时还可以传递参数
    }
    var test=new Child(21);
    console.log(test.age);//21
    console.log(test.name);

    test.name.push(‘bill‘);
    console.log(test.name);//mike,jack,smith,bill

function Parent(age){
        this.name=[‘mike‘,‘jack‘,‘smith‘];
        this.age=age;
    }
    Parent.prototype.run=function(){
        return this.name+‘ are both ‘+this.age;
    }
    function Child(age){
        Parent.call(this,age);//给超类型传参，第二次调用
    }
    Child.prototype=new Parent();//原型链继承，第一次调用
    var test1=new Child(21);//写new Parent(21)也行
    console.log(test1.run());//mike,jack,smith are both 21

    var test2=new Child(22);
    console.log(test2.age);
    console.log(test1.age);
    console.log(test2.run());
    //这样可以使test1和test2分别拥有自己的属性age同时又可以有run方法

function object(o){
        function F(){};
        F.prototype=o;
        return new F();
    }
    var person={
        name:‘nicho‘,
        friends:[‘shell‘,‘jim‘,‘lucy‘]
    }
    var anotherPerson = object(person);
    anotherPerson.name = ‘Greg‘;
    anotherPerson.friends.push(‘Rob‘);
    console.log(anotherPerson.friends);//["shell", "jim", "lucy", "Rob"]

    var yetAnotherPerson = object(person);
    yetAnotherPerson.name = ‘Linda‘;
    yetAnotherPerson.friends.push(‘Barbie‘);
    console.log(yetAnotherPerson.friends);//["shell", "jim", "lucy", "Rob", "Barbie"]

    console.log(person.friends);//["shell", "jim", "lucy", "Rob", "Barbie"]

var person2={
        name:‘nicho‘,
        friends:[‘shell‘,‘jim‘,‘lucy‘]
    };
    var anoP2=Object.create(person2);
    anoP2.name="Greg";
    anoP2.friends.push(‘Rob‘);
    console.log(anoP2.friends);//["shell", "jim", "lucy", "Rob"]

    var yetP2=Object.create(person2);
    yetP2.name="Linda";
    yetP2.friends.push(‘Barbie‘);
    console.log(yetP2.friends);//["shell", "jim", "lucy", "Rob", "Barbie"]

    console.log(person2.friends);//["shell", "jim", "lucy", "Rob", "Barbie"]
    /*以这种方式指定的任何属性都会覆盖原型对象上的同名属性。*/
    var threeP=Object.create(person,{
        name:{value:‘red‘}
    });
    console.log(threeP.name);//red,如果threeP中无name则输出person2里的name值nicho

function object(o){
        function F(){};
        F.prototype=o;
        return new F();
    };
    function createAnother(o){
        var cl=object(o);
        cl.sayHi=function(){
            console.log(‘hi‘);
        }
        return cl;
    };
    var person={
        name:‘nick‘,
        friends:[‘shelby‘,‘court‘,‘van‘]
    }
    var anotherPerson=createAnother(person);
    anotherPerson.sayHi();//hi
    console.log(anotherPerson.name);//nick
    console.log(anotherPerson.friends);//["shelby", "court", "van"]

    /*这个例子中的代码基于 person 返回了一个新对象—— anotherPerson 。 新对象不仅具有 person
     的所有属性和方法，而且还有自己的 sayHi() 方法*/

function SuperType(name){
        this.name=name;
        this.colors=[‘red‘,‘blue‘,‘green‘];
    }
    SuperType.prototype.sayName=function(){
        console.log(this.name);
    }
    function SubType(name,age){
        SuperType.call(this,name);
        this.age=age;
    }
    function object(o){
        function F(){};
        F.prototype=o;
        return new F();
    };
    /*inheritPrototype此函数第一步是创建超类型原型的一个副本。第二步是为创建的副本添加constructor属性，
    * 从而弥补因重写原型而失去的默认的constructor属性，第三步将新创建的对象（副本）赋值给子类型的原型*/
    function inheritPrototype(subType,superType){
        var prototype=object(superType.prototype);//创建对象
        prototype.constructor=subType;//增强对象
        subType.prototype=prototype;//指定对象
    }
    inheritPrototype(SubType,SuperType);
    SubType.prototype.sayAge=function(){
        console.log(this.age);
    }

    var p=new SubType(‘xiaoli‘,24);
    console.log(p.sayName());
    console.log(p.sayAge());
    console.log(p.colors)