例21.3 类型的四种属性
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<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Example 21.3</title>
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<script language="javascript" type="text/javascript">
<!--
function dwn(s)
{
document.write(s + "<br/>");
}
function myClass()
{
var p = 100; //private property; 私有属性
this.x = 10; //dynamic public property 动态公有属性
}
myClass.prototype.y = 20; //static public property or prototype property 原型属性
myClass.z = 30; //static property //静态属性
var a = new myClass();
dwn(a.p); //undefined 私有属性对象无法访问到
dwn(a.x); //10 公有属性
dwn(a.y); //20 公有属性
a.x = 20;
a.z = 40;
dwn(a.x); //20
dwn(a.y); //40 //动态公有属性y覆盖了原型属性y
delete(a.x);
delete(a.y);
dwn(a.x); //undefined 动态公有属性x被删除后不存在
dwn(a.y); //20 动态公有属性y被删除后还原为原型属性y
dwn(a.z); //undefined 类属性无法通过对象访问
dwn(myClass.z); //30 类属性应该通过类访问
-->
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