[读码时间] 用typeof查看数据类型

说明：代码取自网络，注释为笔者学习时添加！

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>用typeof查看数据类型</title>
    <style>
        pre {
            color: green;
            padding: 10px 15px;
            background: #f0f0f0;/*灰色*/
            border: 1px dotted #333;/*黑色*/
            font: 12px/1.5 Courier New;/*行高18px*/
        }

        span {
            color: #999;/*灰黑色*/
        }
    </style>
</head>
<body>
<pre>
&lt;script type="text/javascript"&gt;
    alert(typeof 12345);    <span>//输出number</span>
    alert(typeof "abc");    <span>//输出string</span>
    alert(typeof document);    <span>//输出object</span>
&lt;/script&gt;
</pre>
    <script>
alert("typeof 12345 → " + typeof 12345 + "\
      \n\ntypeof \"abc\" → " + typeof "abc" + "\
      \n\ntypeof document → " + typeof document
      );
    </script>
</body>
</html>
View Code

 

posted @ 2017-02-25 02:54  sx00xs  阅读(144)  评论(0)  编辑  收藏  举报