js继承的几种方式

"use strict";
/*
* 每一个构造函数都有一个原型对象
* 每一个原型对象都包含一个指向构造函数的指针
* 每一个对象都包含一个指针指向原型对象
* 原型对象==实例对象
* 原型对象就包含一个指针指向原型对象
* 结论：层次递进，就构成了原型链
*/
function GrandFather(){
this.name = "张三";
}

GrandFather.prototype.getName = function () {
return this.name;
}

function Parent() {

}

Parent.prototype = new GrandFather();

function Child(){

}

Child.prototype = new Parent();

var child = new Child();
alert(child.getName());

"use strict";
//父子关系，子类的构造函数里调用父类的构造函数
function Parent() {
this.name = "李四";
this.age = 12;
}

function Child() {
Parent.call(this);
}

var child = new Child();
alert(child.name);
alert(child.age);

"use strict";
//组合继承（将构造函数和原型链结合在一起）
function Parent() {
this.name = "李四";
this.age = 12;
}

Parent.prototype.getName = function(){
alert(this.name);
}

function Child() {
Parent.call(this);
}

Child.prototype = new Parent();

var child = new Child();
alert(child.getName());

"use strict";
//寄生式继承
function CreateOther(original){
var clone = Object(original);
clone.getName = function () {
alert(this.name);
}
return clone;
}

var person = {
name:"张三",
age:"11"
}

var otherPerson = CreateOther(person);
person.getName();