摘要：第二個(gè)問(wèn)題是在創(chuàng)建子類型的實(shí)例時(shí)，不能向超類型的構(gòu)造函數(shù)中傳遞參數(shù)。實(shí)際上，應(yīng)該說(shuō)是沒(méi)有辦法在不影響所有對(duì)象實(shí)例的情況下，給炒類型的構(gòu)造函數(shù)傳遞參數(shù)。借用構(gòu)造函數(shù)偽造對(duì)象或經(jīng)典繼承即在子類型構(gòu)造函數(shù)的內(nèi)部調(diào)用超類型構(gòu)造函數(shù)。

許多 OO 語(yǔ)言支持兩種繼承方式：接口繼承和實(shí)現(xiàn)繼承。接口繼承只繼承方法簽名，而實(shí)現(xiàn)繼承則繼承實(shí)際的方法。如前所述，由于函數(shù)沒(méi)有簽名，在 ECMAScript 中無(wú)法實(shí)現(xiàn)接口繼承。 ECMAScript 只支持實(shí)現(xiàn)繼承，而且其實(shí)現(xiàn)繼承主要是依靠原型鏈來(lái)實(shí)現(xiàn)。

基本思想是：利用原型讓一個(gè)引用類型繼承另一個(gè)引用類型的屬性和方法。
構(gòu)造函數(shù)、原型和實(shí)例的關(guān)系：每個(gè)構(gòu)造函數(shù)都有一個(gè)原型對(duì)象，原型對(duì)象都包含一個(gè)指向構(gòu)造函數(shù)的指針，而實(shí)例都包含一個(gè)指向原型對(duì)象的內(nèi)部指針。

jsfunction SuperType() {
    this.property = true;
}
SuperType.prototype.getSuperValue = function() {
    return this.property;
};

function SubType() {
    this.subproperty = false;
}

//繼承了 SuperType
SubType.prototype = new SuperType();

SuperType.prototype.getSubValue = function() {
    return this.subproperty;
}

var instance = new SubType();
alert(instance.getSuperValue());//true

jsalert(instance instanceof Object); //true
alert(instance instanceof SuperType); //true
alert(instance instanceof SubType); //true

jsalert(Object.prototype.isPrototypeOf(instance));//ture
alert(SuperType.prototype.isPrototypeOf(instance));//ture
alert(SubType.prototype.isPrototypeOf(instance));//ture

jsfunction SuperType() {
this.property = true;
}

SuperType.protype.getSuperValue = function() {
return this.property;
}

function SubType() {
this.subproperty = false;
}
//繼承了 SuperType
SubType.prototype = new SuperType();
//添加新方法
SubType.prototype.getSubValue = function() {
return this.subproperty;
};
//重寫超類型中的方法
SubType.prototype.getSuperValue = function() {
return false;
};

var instance = new SubType();

alert(instance.getSuperValue());//false

jsfunction SuperType() {
this.property = true;
}

SuperType.prototype.getSuperValue = function() {
return this.property;
}

function SubType() {
this.subproperty = false;
}

//繼承了 SuperType
SubType.prototype = new SuperType();

//使用字變量添加新方法，會(huì)導(dǎo)致上一行代碼無(wú)效
SubType.prototype = {
getSubValue : function() {
    return this.subproperty;
},
someOtherMethod = function() {
    return false;
}
};

var instance = new SubType();
alert(instance.getSuperValue()); //error 原型鏈被切斷（現(xiàn)在的原型包含的是 Object 的實(shí)例）。

jsfunction SuperType() {
    this.colors = ["red","blue","green"];
}

function SubType() {
    //繼承了 SuperType
    SuperType.call(this);
}

var instance1 = new SubType();
instance1.colors.push("black");
alert(instance1.colors); //"red,blue,green,black"

var instance2 = new SubType();
alert(instance2.colors); //"red,blue,green"

js    function SuperType(name) {
        this.name = name;
    }

    function SubType() {
        //繼承了 SuperType,同時(shí)還傳遞了參數(shù)
        SuperType.call(this,"PaddingMe");

        //實(shí)例屬性
        this.age = 25;
    }

    var instance = new SubType();

    alert(instance.name); //"PaddingMe"
    alert(instance.age); //25

js    function SuperType(name) {
        this.name = name;
        this.colors = ["red","blue","green"];
    }

    SuperType.prototype.sayName = function() {
        alert(this.name);
    }

    function SubType() {
        //繼承屬性
        SuperType.call(this,name);

        this.age = age;
    }

    SubType.prototype = new SuperType();
    SubType.prototype.constuctor = SubType();
    SubType.prototype.sayAge = function() {
        alert(this.age);
    }

    var instance1 = new("PaddingMe",25);
    instance1.colors.push("black");
    alert(instance1.colors); //"red,blue,green,black"
    instance1.sayName; //"PaddingMe"
    instance1.sayAge; //25


    var instance2 = new("hw",26);
    alert(instance2.colors); //"red,blue,green"
    instance2.sayName; //"hw"
    instance2.sayAge; //26

js    function object(o) {
        function F(){}
        F.prototype = o;
        return new F();
    }
    var person = {
        name : "PaddingMe";
        friends ：["hw","wjj","hz"];
    }

    var antherPerson = object(person);
    antherPerson.name = "Hhb";
    antherPerson.friends.push("zxp");

    var yetAntherPerson = object(person);
    yetAntherPerson.name = "Linda";
    yetAntherPerson.friends.push("him");

    alert(person.friends)//"hw,wjj,hz,zxp,him"

js    var person = {
        name : "PaddingMe";
        friends ：["hw","wjj","hz"];
    }
    var antherPerson = Object.create(person);
    antherPerson.name = "Hhb";
    antherPerson.friends.push("zxp");

    var yetAntherPerson = Object.create(person);
    yetAntherPerson.name = "Linda";
    yetAntherPerson.friends.push("him");

    alert(person.friends)//"hw,wjj,hz,zxp,him"

js    var person = {
        name : "PaddingMe";
        friends ：["hw","wjj","hz"];
    }

    var anthorPerson = Object.create(person, {
        name: {
            value:"hehe";
        }
    })

    alert(anthorPerson.name);//"hehe"

js    function createAnother(original) {
        var clone = object(original); //通過(guò)調(diào)用函數(shù)創(chuàng)建一個(gè)新對(duì)象
        clone.sayHi = function() { //以某種方式來(lái)增強(qiáng)這個(gè)對(duì)象
            alert("hi");
        };
        return clone; //返回這個(gè)對(duì)象
    }

    var person = {
        name : "PaddingMe";
        friends ：["hw","wjj","hz"];
    }

    var anthorPerson = createAnother(person);
    anthorPerson.sayHi();//"hi"

jsfunction SuperType(name) {
    this.name = name;
    this.colors = ["red","blue","green"];
}

SuperType.prototype.sayName = function() {
    alert(this.name);
}

function SubType(name,age) {
    SuperType.call(this,name); //第二次調(diào)用SuperType();

    this.age = age;
}

SubType.prototype = new SuperType(); // 第一次調(diào)用SuperType();

SubType.prototype.constuctor = SubType;

SubType.prototype.sayAge = function(){
    alert(this.age);
}

js    function inheritPrototype(subType,superType){
        var prototype = object(superType.prototype); //創(chuàng)建對(duì)象
        prototype.constructor = subType; //增強(qiáng)對(duì)象
        subType.prototype = prototype; // 指定對(duì)象
    }

jsfunction SuperType(name) {
    this.name = name;
    this.colors = ["red","blue","green"];
}

SuperType.prototype.sayName = function() {
    alert(this.name);
}

function SubType(name,age) {
    SuperType.call(this,name); //第二次調(diào)用SuperType();

    this.age = age;
}

inheritPrototype(SubType,SuperType);

SubType.prototype.sayAge = function(){
    alert(this.age);
}