function Person(name,sex){    this.name = name;    this.sex = sex;}Person.prototype = {    getName:function(){return this.name},    getSex:function(){return this.sex}}var liu = new Person("lcy","female");//创建一个空白对象//拷贝Person.prototype中的属性到空对象中（内部实现为一个隐藏的链接）//将这个对象通过this关键字传递到构造函数中并执行构造函数//将这个对象赋值给对象liuconsole.log(liu.getName());//lcyPerson.prototype.age = 22;console.log(liu.age);//22liu.age = 24;console.log(liu.age);//24delete liu.age;console.log(liu.age);//22

function Employee(name,sex,employeeID){    this.name=name;    this.sex=sex;    this.employeeID=employeeID;}//将Employee的原型指向Person的一个实例Employee.prototype=new Person();
Employee.prototype.constructor=Employee;Employee.prototype.getEmployeeId=function(){return this.employeeID;};var chen=new Employee("chen","female",001);console.log(chen.getName());