请看下面的例子：
var Person = function(name,age){ this.name = name; this.age = age || "未填写"; this.hobbys = []; } Person.prototype = { sayName:function(){ console.log(this.name); }, sayAge:function(){ console.log(this.age); }, addHobby:function(hobbys){ this.hobbys = this.hobbys.concat(hobbys); } } var person1 = new Person("Jane","20"); var person2 = new Person("TabWeng","21"); person1.addHobby(['sing','drawing']); person2.addHobby(['football','study','running']); person1.sayName(); console.log(person1.hobbys.toString()); person2.sayName(); console.log(person2.hobbys.toString()); 运行结果：
Jane sing,drawingTabWeng football,study,running
这在中讲过，把可以共用的属性和方法写在原型上，需要每个实例各自都有的副本的属性和方法放在构造函数中。
现在有个问题，名称的输入不能有数字，要怎么解决呢？解决的方法可以写一个检查名称的函数，这个函数写在原型上。
var Person = function(name,age){ //校验名称 if(this.checkName(name)){ throw new Error("名字 "+name+" 不能存在数字"); } this.name = name; this.age = age || "未填写"; this.hobbys = []; } Person.prototype = { //校验函数 checkName:function(name){ re = /\d/; return re.test(name); }, sayName:function(){ console.log(this.name); }, sayAge:function(){ console.log(this.age); }, addHobby:function(hobbys){ this.hobbys = this.hobbys.concat(hobbys); } } var person1 = new Person("Helen666","20"); var person2 = new Person("TabWeng","21"); person1.addHobby(['sing','drawing']); person2.addHobby(['football','study','running']); person1.sayName(); console.log(person1.hobbys.toString()); person2.sayName(); console.log(person2.hobbys.toString()); 这段代码中，我们写了一个checkName()函数，来校验名称，暂且只是校验不能有数字吧，然后再构造函数里的第一行代码中进行校验，若校验不通过，则抛出异常。
Error: 名字 Helen666 不能存在数字
这样就做到了一个基本的封装，实现内部校验。
但是又有个问题，我们还可以这样来定义名称：
var person1 = new Person("Helen","20"); person1.name = "Helen666"; person1.sayName(); //Helen666 这样名称还是可以修改为不合法的名称，于是我们想到用get方法 和set方法来做控制，只能通过set方法来赋值，同时通过set方法进行校验，而通过get方法来获得值。现在的代码修改如下：
// Interfacevar People = new Interface("People",["setName","getName","setAge","getAge","addHobby","getHobby","sayName","sayAge"]); var Person = function(name,age){ //implement People this.setName(name); this.setAge(age); this._hobbys = []; } Person.prototype = { //校验函数 checkName:function(name){ re = /\d/; return re.test(name); }, sayName:function(){ console.log(this._name); }, sayAge:function(){ console.log(this._age); }, addHobby:function(hobbys){ this._hobbys = this._hobbys.concat(hobbys); }, getHobby:function(){ return this._hobbys; }, setName:function(name){ if(this.checkName(name)){ throw new Error("名字 "+name+" 不能含有数字"); } this._name = name; }, getName:function(){ return this._name; }, setAge:function(age){ this._age = age || "未设置"; }, getAge:function(){ return this._age