<!DOCTYPE HTML>
<html >
<head>
<meta charset="UTF-8">
<title>数值型</title>
</head>
<body>
<script type="text/javascript">
var num = 1988;
/*
if(!isNaN(num)){
document.write("非数值型");
}
*/
if(num.constructor == Number){
document.write("数值型");
document.write(typeof num.toString());
}
document.write("<br/>");
document.write(Number.MAX_VALUE + "<br/>");
document.write(Number.MIN_VALUE + "<br/>");
var a = 10 ;
var b = a++ ;//先执行再运算
var c = ++a ;//先运算再执行
//document.write(a + "<br/>");
document.write(b + "<br/>");
document.write(c + "<br/>");
</script>
</body>
</html>