javascript 学习笔记——对象、命名空间
记录以下网址的javascript core crash章节http://courses.coreservlets.com/Course-Materials/ajax-basics.htmlhttp://dl.iteye.com/upload/attachment/0062/0017/64cb536a-772f-3611-8266-2304cd11b3ce.png
<!-- LCTestJS_Object.htmlversion: 2012_01_11 --><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>测试javascript的对象version: 2012_01_11</title><style>h3 {color: #FFF;background-color: #09F;font-style: normal;font-weight: bold;}h4 {font-weight: bolder;color: #d00;background-color: #DDD;}h5{background-color: #FFC;color: #000;font-size: 18px;}</style><script type="text/javascript">function printSpace(n){//输出n个空格if(n==null)document.write();else for(var i=0;i<n;i++)document.write('&nbsp;');}function print(str,description){//新起一段输出str，之后空6格，再输出descriptiondocument.write("<p>"+str);printSpace(6);if(description!=null)document.write("//"+description);}</script></head><body><h2>测试javascript的对象 version: 2012_01_11</h2><h3>构造函数</h3><h4>构造函数内成员变量必须用this指定；构造函数外可以追加成员变量(或函数)</h4><h5>function Circle(r){<br>this.radius=r;//构造函数内成员变量必须用this指定；<br>//成员函数，每个实例一个，耗内存啊(不推荐)<br>this.getAreaVer1=function(){//this都是必须写的！！！<br>return Math.PI*this.radius*this.radius;<br>}<br>//类变量，不是全局的？<br>Circle.prototype.radiusClass=5;<br>//类函数，注意前面是类名(Circle)而非this！！！实例共享一个<br>Circle.prototype.getArea=function(){//this都是必须写的！！！<br>return Math.PI*this.radius*this.radius;<br>}<br>}<br>var c=new Circle(1);var c2=new Circle(2); c2.radiusClass=3;</h5><script type="text/javascript">function Circle(r){this.radius=r;//构造函数内成员变量必须用this指定；//成员函数，每个实例一个，耗内存啊(不推荐)this.getAreaVer1=function(){//this都是必须写的！！！return Math.PI*this.radius*this.radius;}//类变量，不是全局的？Circle.prototype.radiusClass=5;//类函数，注意前面是类名(Circle)而非this！！！实例共享一个Circle.prototype.getArea=function(){//this都是必须写的！！！return Math.PI*this.radius*this.radius;}}var c=new Circle(1);c.radiusClass=3;var c2=new Circle(2);document.write("<p>c.radiusClass="+c.radiusClass);document.write("<p>c2.radiusClass="+c2.radiusClass+"\t//没变啊！");document.write("<p>c.getArea()=\t"+c.getArea());document.write("<p>c2.getArea()=\t"+c2.getArea());</script><!-- ---------------------- --><h3>静态方法、命名空间（用类的函数模拟）</h3><h4></h4><h5>var obj1={p:1}; var obj2={p:2};<br>function minus(x,y){return (this.p+x-y);}</h5><script type="text/javascript">var Util={};//这样就可以当做命名空间了！！Util.minus=function(x,y){return x-y;}Util.add=function add(x,y){return x+y};//两个处addprint("(typeof Util.add)="+(typeof Util.add));print("(typeof Util.minus)="+(typeof Util.minus));print("(typeof add)="+(typeof add),"囧啊，还是没定义;但据说调试器可见");print("(typeof minus)="+(typeof minus));print("Util.minus="+Util.minus);print("Util.add="+Util.add,"有函数名，写两遍add还是有用滴");</script><!-- ---------------------- --><h3>JSON (JavaScript Object Notation)</h3><h4>可用于可变参数函数</h4><h5>var someObject = { property1: value1,property2: value2,... };<p>function test(x){<br>if(x.property1!=null)...<br>}</h5><script type="text/javascript">document.write("<p>minus.call(obj1,9,4)=" + minus.call(obj1,9,4));</script></body></html>
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