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<html>
<head>
<meta charset="utf-8">
<title>菜鸟学堂(edu.jb51.net)</title>
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<p id="demo">单击按钮来调用新的myMet()方法,并显示55一半数量值,使用新的构造函数myProp（）。</p>
<button onclick="myFunction()">点我</button>
<script>
Number.prototype.myMet=function(){
this.myProp=this.valueOf()/2;
}
function myFunction(){
var d = new Number(55);
d.myMet();
var x=document.getElementById("demo");
x.innerHTML=d.myProp;
</script>
</body>
</html>