<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script>
var num1 = new Number(111);
console.log(num1);
var num2 = Number("111");
console.log(num2);
var aaa = new Strings(222);
console.log(aaa);
var bbb = Strings("333");
console.log(bbb);
function Strings(num){
this["[[PrimitiveValue]]"] = num;
return num/1;
}
</script>
</body>
</html>
原文：http://www.cnblogs.com/sj1988/p/6579823.html