js继承实例

1.js原型(prototype)实现继承

function Person(name, age){

  this.name = name;

  this.age = age;

}

//给它的原型直接添加属性或方法

Person.prototype.love = "alin";

Person.prototype.sayHello = function(){

  console.log(this.name);//lilinwei

}

var per = new Person("lilinwei", 2);

per.sayHello();

console.log(per.love);//alin

function Student(){ }

Student.prototype = new Person("Leeon", 22);

Student.prototype.grade = 4;

Student.prototype.intr = function(){

  console.log(this.grade);

}

var stu = new Student();

stu.sayHello();//Leeon

stu.intr();//4      

2.构造函数继承

function Parent(name){

  this.name = name;

  this.sayName = function(){

  console.log("Parent:" + this.name);

  }

}

function Child(name, age){

  this.tempMethod = Parent;

  this.tempMethod(name);

  this.age = age;

  this.sayName = function(){

  console.log("Child" + this.name + "age" + this.age);

  }

}

var parent = new Parent("zzl");

parent.sayName();//zzl

var child = new Child("llw", 2);

child.sayName();//llw 2    

3.call/apply

function Person(name, age){

  this.name = name;

  this.age = age;

  this.say = function(){

  console.log("姓名：" + name);

  }

}

//call

function Student1(name, age){

  Person.call(this, name, age);

}

//apply

function Student2(name, age){

  Person.apply(this, [name, age]);

  //Person.apply(this, arguments);等价于上一句

}

var per = new Student1("zzl", 88);

per.say();//姓名：zzl