prototype 函数被创建的时候，会自动生成一个prototype对象，一个预设对象属性
//定义所有实体都能公用的属性 function Person(name,age){ //... } Person.prototype.hi = function(){} function Student(name,age,className) { Person.call(this,name,age); this.calssName = className; } //为了使继承后的Student上的prototype不影响Person上的prototype,用Object.create() Student.prototype=Object.create(Person.prototype);//创建一个空对象,原型指向Person的prototype Student.prototype.constructor=Student; //不然会指向Person //修改prototype的属性，会影响到在这之后的对象，不会影响到之前的 foo.prototype.z=3; 'z' in obj;//会追溯到原型 obj.hasOwnProperty('z');//只查看本类instanceof instanceof比较两边是否有一样的prototype
调用基类：
//call Person.prototype.init = function(){}; Student.prototype.init=function() { Person.prototype.init.apply(this,argument); }链式调用
function ClassManager(){} ClassManager,prototype.addClass = function(str) { //... } var manager = new ClassManager(); manager.addClass().addClass().ddClass();实践：
!function(global) { function DetectorBase(configs) { if(!this instanceof DetectorBase) { throw new Error('Do not invoke without new');//防止不new就直接调用类 } this.configs = configs; this.analyze(); } } DetectorBase.prototype.detect = function() { throw new Error('Not implemented');//由于基类不是具体的探测器，所以需要子类继承实现，基类不实现 }; DetectorBase.prototype.analyze = function() { console.log('analyzing'); this.data = "###data###"; }; } function LinkDetector(links) { if(!this instanceof LinkDetector) { throw new Error('Do not invoke without new'); } this.links = links; DetectorBase.apply(this,arguments); } function ContainerDetector(contaniers) { if(!this instanceof ContainerDetector) { throw new Error('Do not invoke without new.'); } this.containers = containers; DetectorBase.apply(this,aguments); } //继承 inherit(LinkDetector, DetectorBase); inherit(ContainerDetector, DetectorBase); LinkDetector.prototype.detect = function() { console.log('Loading data:'+this.data); console.log('Link detection started.'); console.log('Scaning links' + this.links); }; ContainerDetector.prototype.detect = function() { console.log('Loading data:'+this.data); console.log('Container detection started.'); console.log('Scaning containers'+this.containers); }; Object.defineProperties(global,{//其余属性都是false linkDetector:{value:LinkDeteor}, ContainerDetector:{value:ContainerDetector}, DetectorBase:{value:DetectorBase} }); function inherit(subClass,superClass) { subClass.protptype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; } Object.freeze(DetectBase); Object.freeze(DetectBase.prototype); Object.freeze(LinkDetector); Object.freeze(LinkDetector.prototype); Object.freeze(ContainerDetector); Object.freezeContainerDetector.prototype); }(this); var cd = new ContainerDetector('#abc #def #ghi'); var id = new LinkDetector('http://www.taobao.com'); cd.detect(); id.detect();