JavaScript-面向对象

一、JavaScript面向对象语言特性：

*传统的面向对象编程语言中，通常对象是由类派生而来的，而类定义来了成员属性和成员方法。

*JavaScript编程语言中没有类的概念，它是一门基于原型（prototype）的面向对象编程的语言。

*JavaScript面向对象这个词其实是多余的，因为JavaScript这门语言就是完全面向对象的。

*对象是组成Javascript编程语言的基本单元，JavaScript编程语言中的一切都是对象。

二、JavaScript对象化能力

*在JavaScript语言中只有object和function两种东西有对象化的能力。

<script type="text/javascript">

//<![CDATA[

var NoteBook = {} //创建一个笔记本对象

NoteBook.name = "MacBook Pro";

NoteBook.model = "MC374";

NoteBook.say = function(){

document.write("<h1>计算机的名称是" + this.name + "型号是" + this.model + "</h1>")

}

NoteBook.say();

//NoteBook['say']();

var NoteBook = function(){} //创建一个笔记本函数对象

NoteBook.name = "SAMSUNG";

NoteBook.model = "B002";

NoteBook.say = function(){

document.write("<h1>计算机的名称是" + this.name + "型号是" + this.model + "</h1>")

}

NoteBook['say']();

//]]>

</script>

说明：

所有 XML 文档中的文本均会被解析器解析。

只有 CDATA 区段（CDATA section）中的文本会被解析器忽略。

For instance:

以下的例子展示的是青蛙的进化过程.

<script type="text/javascript">

//<![CDATA[

var life = {}; //光溜溜的生命对象，这种方式相当于是var life = new Object();

for(life.age = 1;life.age<=4;life.age++){

switch(life.age){

case 1:

life.body = "卵细胞";

life.say = function(){

document.write("<h1>" + this.age + this.body + "</h1>")

};

break;

case 2:

life.tail = "尾巴";

life.gill = "腮";

life.body = "蝌蚪";

life.say = function(){

document.write("<h1>" + this.age + this.body + " - " + this.tail + "," + this.gill + "</h1>");

};

break;

case 3:

delete life.tail;

delete life.gill;

life.legs = "四条腿";

life.lung = "肺";

life.body = "青蛙";

life.say = function(){

document.write("<h1>" + this.age + this.body + " - " + this.legs + "," + this.lung + "</h1>");

};

break;

case 4:

life.arm = "两只手臂";

life.legs = "两条腿";

life.lung = "肺";

life.body = "青蛙王子";

life.say = function(){

document.write("<h1>" + this.age + this.body + " - " + this.arm + "," + this.legs + "," + this.lung + "</h1>");

};

break;

}

life.say();

}

//]]>

三、JavaScript对象表示法

<script type="text/javascript">

//<![CDATA[

/*

JSON为创建对象提供了简单的方法,JSON(JavaScript Object Notation),中文称JavaScript对象表示法

*/

//创建一个没有任何属性的对象

var o = {};

//创建一个对象并设置属性及初始值

var person = {name: "Angel", age: 18, married: false};

//创建一个对象并设置属性和方法

var speaker = {text: "Hello World", say: function(){alert(this.text)}};

//创建一个更复杂的对象,嵌套其他对象和对象数组等

var company = {

//成员属性

name: "Microsoft",

product: "softwares",

//对象

chairman: {name: "Bill Gates", age: 53, Married: true},

//对象数组 employees: [{name: "Angel", age: 26, Married: false}, {name: "Hanson", age: 32, Marred: true}],

//成员方法

readme: function() {document.write(this.name + " product " + this.product);}

};

//]]>

</script>

四、php 与JavaScript 的面向对象的实现：

<?php

//人类

class Person{

public $name;

public $age;

public $sex;

public function __construct($name, $age, $sex){

$this->name = $name;

$this->age = $age;

$this->sex = $sex;

}

public function say(){

echo "<h1>PHP".$this->name." - ".$this->age." - ".$this->sex."</h1>";

}

}

$p = new Person("于亚东",25,"男");

$p->say()

?>

<script type="text/javascript">

//<![CDATA[

//定义一个构造函数相当于类

function Person(name, age, sex){

this.name = name;

this.age = age;

this.sex = sex;

this.say = function(){

document.write("<h1>JavaScript" + this.name + " - " + this.age + " - " + this.sex + "</h1>");

}

}

var p = new Person("刘悦伶",23,"女");

p.say();

//]]>