16-构造函数原理 

<!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>

　　

posted @ 2017-03-19 11:39  北漂阿猫  阅读(294)  评论(0)    收藏  举报