[原]JavaScript学习笔记(六.继承)

1.单继承，使用call()方法

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//父类function Father(name,age){this.Name = name;this.Age = age;this.Intro = function(){alert("hello, I am" + this.Name);}}//子类function Child(name,age){Father.call(this,name,age);//实现继承！并且调用父类的构造方法,this是当前对象       //      Father.apply(this, new Array(name,age));//跟call一样的功能this.Code = function(){alert("I am coding");}}var father = new Father("father",50);var child = new Child("child",23);father.Intro();child.Intro();//子类调用继承自父类的方法child.Code();//子类调用自己的方法

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2.单继承?

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//父类function Father(name,age){this.Name = name;this.Age = age;this.Intro = function(){alert("hello, I am" + this.Name);}}//子类function Child(name,age){this.Constructer = Father;//指定方法为上面那个父类的那个方法,跟下面的方法合起来实现继承this.Constructer(name,age);  //调用该方法:注意调用的时候，是Child对象调用，那么调用完，Child的2个属性也就赋值了，而且多了1个方法delete this.constructor; // 删除这个方法，是因为不想覆盖父类的相关方法和属性?this.Code = function(){alert("I am coding");}}var father = new Father("father",50);var child = new Child("child",23);father.Intro();child.Intro();//子类调用继承自父类的方法child.Code();//子类调用自己的方法

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3.多继承

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//父类1function Father(name,age){this.Name = name;this.Age = age;this.Intro = function(){alert("hello, I am" + this.Name);}}//父类2function Father_2(pay){this.Pay = pay;this.showPay = function(){alert("your pay is " + this.Pay);}}//子类function Child(name,age,pay){this.Constructer = Father;//指定方法为上面那个父类的那个方法this.Constructer(name,age);  //调用该方法:注意调用的时候，是Child对象调用，那么调用完，Child的2个属性也就赋值了，而且多了1个方法delete this.Constructor; // 删除这个方法，是因为不想覆盖父类的相关方法和属性?this.Constructer2 = Father_2;this.Constructer2(pay);delete this.Constructer2;this.Code = function(){alert("I am coding");}}var father = new Father("father_1",50);var fater_2 = new Father_2(5000);var child = new Child("zxh",23,10000);  //I am coding. father.Intro();//hello, I am father'_1child.Intro();//调用从第一个父类继承的方法hello,I am zxh. child.Code();//I am codingchild.showPay();//调用从第二个父类继承的方法 your pay is 10000

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4.多继承2

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//父类构造方法function Father(name,age){this.Name = name;this.Age = age;}//父类的方法Father.prototype.Intro = function(){alert("I am father");}//子类构造方法function Child(name,age){Father.call(this,name,age);//调用父类构造方法，得到各个属性}Child.prototype = new Father();  //实现继承//定义子类自己的方法Child.prototype.Code = function(){alert("I am coding !");}//覆盖父类的方法[如果不指定上面的继承，其实也就相当与自己新定义一个一样]Child.prototype.Intro = function(){alert("I am " + this.Name);}var father = new Father();var child = new Child("zxh",23);father.Intro(); //父类调用自身方法child.Intro();  //子类调用覆盖父类的方法child.Code();//子类调用自己定义的方法

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