javascript—面向对象

1、//example 1

var Person = function () { };

var p1 = new Person();

p1.name = "jack";

p1.age = 25;

var p2 = new Person();

alert(p1.name);  //jack

alert(p2.name);  //undefined

//example 2

function CreateUser(name,qq) {

this.name = name;

this.email = qq;

};

window.onload = function () {

obj1 = new CreateUser(‘a‘,321);

var obj2 = new CreateUser(‘b‘,123);

alert(obj1.email);

alert(obj2.email);

};

2、继承

function A(email) {

this.name = ‘a‘;

this.email = email;

}

A.prototype.show = function () {

alert(this.email);

};

//继承A

function B(email) {

A.call(this, email);

}

////引用赋值定义A.prototype.say B也具有say()方法

//B.prototype = A.prototype;

//B.prototype.say = function () {

//    alert(‘My Name is ‘+this.name);

//}

for (var i in A.prototype) {

B.prototype[i] = A.prototype[i]

}

B.prototype.say = function () {

alert(‘My Name is ‘ + this.name);

}

var objA = new A(‘[email protected]@.com‘);

var objB = new B(‘[email protected]@.com‘);

objA.say(); //错误