JavaScript中原型与继承（简单例子）

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liu
console.log(liu.getName());//lcy
Person.prototype.age = 22;
console.log(liu.age);//22
liu.age = 24;
console.log(liu.age);//24
delete 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());