简单的方式

function Person() {    this.name = 'person';}Person.prototype.say = function() {};function Child() {    this.name = 'child';}Child.prototype = new Person(); var child = new Child();

缺点：其实child并不需要person里面的name属性

借用构造函数

function Person() {    this.name = 'person';}Person.prototype.say = function() {};function Child() {     Person.call(this, arguments)}var child = new Child();

缺点：仅会复制父类对象的属性作为子类自身的属性, 仅仅是复制**

优点：可以获得父对象自身的真实副本，子类和父类没有关系，不会影响到父类**

借用构造函数是实现多继承

function CatWings() {     Cat.call(this, arguments)     Brid.call(this, arguments)}

借用构造函数和实现原型

function Person() {    this.name = 'person';}Person.prototype.say = function() {};function Child() {     Person.call(this, arguments)    // this.name = 'child'}Child.prototype = new Person()var child = new Child();delete child.name;// 可以看到访问：child.name的是prototype的

name属性被继承了2次

缺点：所有从Person继承的类，都是可以更改到Person的原型方法

临时构造函数

function inherit(Child, Parent) {    var F = function(){}    F.prototype = Parent.prototype;    Child.prototype = new F();    // Child.prototype.constructor = Child    // Child.superclass = Parent.prototype;}// 每次都要创建一个空的Fvar inherit = (function(){    var F = Function(){};    return function() {        F.prototype = Parent.prototype;        Child.prototype = new F();        // Child.prototype.constructor = Child        // Child.superclass = Parent.prototype;    }})();

Klass

var Klass = function (Parent, props) {    if(props == undefined && typeof Parent == 'object') {        props = Parent;        Parent = null;    }    Parent = Parent || {};    props = props || {};    var Child = function() {        if(Child.superclass.hasOwnProperty('__construct')) {            Child.superclass['__construct'].apply(this, arguments);        }        if(Child.prototype.hasOwnProperty('__construct')) {            Child.prototype['__construct'].apply(this, arguments);        }    };    var F = function() {};    F.prototype = Parent.prototype;    Child.prototype = new F();    Child.prototype.constructor = Child;    Child.superclass = Parent.prototype;    for(var i in props) {        if(props.hasOwnProperty(i)) {            Child.prototype[i] = props[i];        }    }    return Child;}function Animal() {}Animal.prototype.__construct = function(name) {    this.name = name};Animal.prototype.getName = function() {    return this.name;};var Dog = Klass(Animal, {    __construct: function(name, age) {        this.age = age;    },    run: function() {        console.log('My name is %s, I\'m %s years old ,  I\'m Running', this.getName(), this.age);    }});var dog = new Dog('xixi', 26)