//繼承function Person(name,sex){ this.name=name; this.sex=sex;}Person.prototype.sayName=function(){ alert(this.name);}Person.prototype.saySex=function(){ alert(this.sex);}function Worker(name,sex,job){ //繼承person類  Person.call(this,name,sex) //這里的this指的是Worker類的實例，如下面的'W' ,把W傳入Person構造函數，這時W偽裝成Person構造函數里的this this.job=job;}//Worker.prototype=Person.prototype;//如果這樣負值原型，子類的sayJob方法Person父類也會有sayJob方法，因為是引用傳遞//改成如下方式則子類不會影響父類：for(var i in Person.prototype){ Worker.prototype[i]=Person.prototype[i];}Worker.prototype.sayJob=function(){ alert(this.job);}var p=new Person('lisi','男');//alert(p.sayJob);var w=new Worker('zhangsan','男','打醬油的');w.sayName();w.saySex();w.sayJob();