JavaScript面向对象之继承

1.      原型链继承：

function SuperType(){	this.PRoperty = true;}SuperType.prototype.getSuperValue = function (){	return this.property;}function SubType(){	this.subproperty = false;}SubType.prototype = new SuperType();SubType.prototype.getSubValue = function (){	return this.subproperty;}var instance = new SubType();alert(instance.getSuperValue());alert(instance instanceof Object);alert(instance instanceof SuperType);alert(instance instanceof SubType);alert(Object.prototype.isPrototypeOf(instance));alert(SuperType.prototype.isPrototypeOf(instance));alert(SubType.prototype.isPrototypeOf(instance));
问题1.包含引用类型值的原型。
问题2.不能像超类型的构造方法传参。
2.借用构造函数（constructor stealing）(伪造对象或经典继承)
(1)无参：
function SuperType(){	this.colors = ['red','blue','green'];}function SubType(){	SuperType.call(this);}var instance1 = new SubType();instance1.colors.push("black");alert(instance1.colors);	var instance2 = new SubType();var instance3 = new SuperType();alert(instance3.colors);(2)传参：
function SuperType(name){	this.name = name;}function SubType(){	SuperType.call(this,"zhangsan");	this.age = 20;}var instance1 = new SubType();alert(instance1.name);  //zhangsanalert(instance1.age);  //20var instance2 = new SuperType();alert(instance2.name);  //undefinedalert(instance2.age);  //undefined
问题：方法在构造函数中定义，无法复用。
3.组合继承（combination inheritance）(伪经典继承)
function SuperType(name){	this.name = name;	this.colors = ["red","blue","green"];}SuperType.prototype.sayName = function(){	alert(this.name);}function SubType(name,age){	//继承属性	SuperType.call(this,name);	this.age = age;}//继承方法SubType.prototype = new SuperType();SubType.prototype.sayAge = function(){	alert(this.age);}var instance1 = new SubType("zhangsan",20);instance1.colors.push("black");alert(instance1.colors);    // red,blue,green,blackinstance1.sayName();  //zhangsaninstance1.sayAge();   // 20var instance2 = new SubType("lisi",30);alert(instance2.colors);  // red,blue,greeninstance2.sayName();  //lisiinstance2.sayAge();  // 304. 原型式继承（Prototypal inheritance）
function object(o){	function F(){}	F.prototype = o;	return new F();}var person = {	name:"zhangsan",	friends :["guojing","huangrong"]};var anotherPerson = object(person);anotherPerson.name = "lisi";anotherPerson.friends.push("zhoubotong");var yetAnotherPerson = object(person);yetAnotherPerson.name = "wangwu";yetAnotherPerson.friends.push("yidengdashi");alert(person.friends);  //  guojing,huangrong,zhoubotong,yidengdashi5.寄生式继承（parasitic）
function object(o){	function F(){}	F.prototype = o;	return new F();}function createAnother(original){	var clone = object(original);	clone.sayHi = function(){		alert("hello");	};	return clone;}var person = {	name:"zhangsan",	friends :["guojing","huangrong"]};var anotherPerson = createAnother(person);//anotherPerson.sayHi();  //helloanotherPerson.name = "lisi";anotherPerson.friends.push("zhoubotong");var yetAnotherPerson = object(person);yetAnotherPerson.name = "wangwu";yetAnotherPerson.friends.push("yidengdashi");alert(person.friends);  //  guojing,huangrong,zhoubotong,yidengdashialert(anotherPerson.friends);  //  guojing,huangrong,zhoubotong,yidengdashialert(yetAnotherPerson.friends);  //  guojing,huangrong,zhoubotong,yidengdashi6.寄生组合式继承
function object(o){	function F(){}	F.prototype = o;	return new F();}function inheritPrototype(subType,superType){	var prototype = object(superType.prototype);	prototype.constructor = subType;	subType.prototype = prototype;}function SuperType(name){	this.name = name;	this.colors = ["red","blue","green"];}SuperType.prototype.sayName = function(){	alert(this.name);}function SubType(name,age){	SuperType.call(this,name);	this.age = age;}inheritPrototype(SubType,SuperType);SubType.prototype.sayAge = function(){	alert(this.age);}var instance = new SubType("zhangsan",30);alert(instance.name);  //zhangsaninstance.sayName();  //zhangsan	instance.sayAge();   // 30