[TOC] ## **在JavaScript中實現繼承的方法：** 1）原型鏈（prototype chaining） 2）call()/apply() 3）混合方式(prototype和call()/apply()結合) 4）對象冒充 ### （1）prototype原型鏈方式： ``` function teacher(name){ this.name = name; } teacher.prototype.sayName = function(){ console.log("name is "+this.name); } var teacher1 = new teacher("xiaoming"); teacher1.sayName(); function student(name){ this.name = name; } student.prototype = new teacher() var student1 = new student("xiaolan"); student1.sayName(); // name is xiaoming // name is xiaolan ``` ### （2）call()/apply()方法 ``` function teacher(name,age){ this.name = name; this.age = age; this.sayhi = function(){ alert('name:'+name+", age:"+age); } } function student(){ var args = arguments; teacher.call(this,args[0],args[1]); // teacher.apply(this,arguments); } var teacher1 = new teacher('xiaoming',23); teacher1.sayhi(); var student1 = new student('xiaolan',12); student1.sayhi(); // alert: name:xiaoming, age:23 // alert: name:xiaolan, age:12 ``` ### （3）混合方法【prototype,call/apply】 ``` function teacher(name,age){ this.name = name; this.age = age; } teacher.prototype.sayName = function(){ console.log('name:'+this.name); } teacher.prototype.sayAge = function(){ console.log('age:'+this.age); } function student(){ var args = arguments; teacher.call(this,args[0],args[1]); } student.prototype = new teacher(); var student1 = new student('xiaolin',23); student1.sayName(); student1.sayAge(); // name:xiaolin // age:23 ``` ### （4）對象冒充 ``` function Person(name,age){ this.name = name; this.age = age; this.show = function(){ console.log(this.name+", "+this.age); } } function Student(name,age){ this.student = Person; //將Person類的構造函數賦值給this.student this.student(name,age); //js中實際上是通過對象冒充來實現繼承的 delete this.student; //移除對Person的引用 } var s = new Student("小明",17); s.show(); var p = new Person("小花",18); p.show(); // 小明, 17 // 小花, 18 ```