<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
</head>
<body>
<script type="text/javascript">
var life = {};
for(life.age = 1; life.age <= 3; life.age++)
{
switch(life.age)
{
case 1: life.body = "卵细胞";
life.say = function(){alert(this.age+this.body)};
break;
case 2: life.tail = "尾巴";
life.gill = "腮";
life.body = "蝌蚪";
life.say = function(){alert(this.age+this.body+"-"+this.tail+","+this.gill)};
break;
case 3: delete life.tail;
delete life.gill;
life.legs = "四条腿";
life.lung = "肺";
life.body = "青蛙";
life.say = function(){alert(this.age+this.body+"-"+this.legs+","+this.lung)};
break;
};
life.say();
}
</script>
</script>
</body>
</html>
原文：http://www.cnblogs.com/jflover/p/6674964.html