JS面向对象练习

<script type="text/javascript">
    //1.可以通过new对象的方法，称之为“构造函数”,采用pascal命名法
    function Person(name,age,email) {
        this.name = name;
        this.age = age;
        this.email = email;
        this.sayHello = function () {
            alert('hi,我叫' + this.name + '我今年' + this.age + '岁了');
        };
    }
    var zs = new Person('张三', 18, '[email protected]');
    var ls = new Person('李四', 22, '[email protected]');

    zs.sayHello();
    ls.sayHello();
    //2.给“构造函数”创建一个私有的“字段”，并用两个函数模拟属性
    function Person2(name, age, email) {
        this.name = name;
        this.age = age;
        this.email = email;
        this.sayHi = function () {
            alert('我是：' + this.name + '今年:' + this.age + '岁了，邮箱是:' + this.email);

        };
        var _gender;
        this.getGender = function () {
            return _gender
        };
        this.setGender = function (gender) {
            if (gender == '男' || gender=='女') {
                _gender = gender;
            }
            else {
                alert('性别别乱填，小心变了哦');
            } 
        }
    }
    var mtt = new Person2('马婷婷', 22, '[email protected]');
    var ltt = new Person2('老太太', 88, '[email protected]');
    mtt.sayHi();
    ltt.sayHi();
    mtt.setGender('x');

    //3.校验实例instanceof 相当于C#中的is(如果是属于类返回true，不属于返回false)

    if (mtt instanceof Person2) {
       document.write('没错,mtt就是Person2');

    };
    //4.通过对象字面量创建对象(只用一次的对象，不创建"构造函数")
    var wll = {
        user_name: '王拉拉',
        user_age: 18,
        user_gender: '女神',
        sayHi: function () {
            alert('我叫' + this.user_name + '今年' + this.user_age);
        }
    };
    wll.sayHi();