1.原型鏈

// 基本思想是利用原型讓一個引用類型繼承另一個引用類型的屬性和方法 
     function SuperType () {
        this.superValue = true; 
    }

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

    function SubType () {
        this.subValue = false;
    }
    // 繼承SuperType
    SubType.prototype = new SuperType();

    SubType.prototype.getSubValue = function () {
        return this.subValue
    }

    var instance = new SubType();

    console.log(instance.getSuperValue()); // true

    // 這樣會有一個問題，當(dāng)SubType的一個實(shí)例改變了其中的一個屬性，其所有的實(shí)例都被更改了這個屬性

2.借用構(gòu)造函數(shù)

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

    function SubType () {
        SuperType.call(this);
    }

    var instance1 = new SubType();
    instance1.colors.push('black');
    console.log(instance1.colors); // ["red", "blue", "green", "black"]

    var instance2 = new SubType();
    console.log(instance2.colors); // ["red", "blue", "green"]

3.組合繼承

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

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

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

    // 繼承方法
    SubType.prototype = new SuperType();

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

    var instance1 = new SubType('silva', 26);
    instance1.colors.push('black');
    console.log(instance1.colors)
    instance1.sayName();
    instance1.sayAge();

    var instance2 = new SubType('mike', 16);
    console.log(instance2.colors)
    instance2.sayName();
    instance2.sayAge();

  // 組合繼承避免了原型鏈和構(gòu)造函數(shù)的缺陷，融合了它們的優(yōu)點(diǎn)

4.寄生組合式繼承

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

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

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

    // 繼承方法
    SubType.prototype = new SuperType();
    // 修正constructor屬性
    SubType.prototype.constructor = SubType;
    SubType.prototype.sayAge = function () {
        console.log(this.age);
    }

    var instance1 = new SubType('silva', 26);
    instance1.colors.push('black');
    console.log(instance1.colors)
    instance1.sayName();
    instance1.sayAge();

    var instance2 = new SubType('mike', 16);
    console.log(instance2.colors)
    instance2.sayName();
    instance2.sayAge();