JS 数据的类型

 1 <!DOCTYPE html>
 2 <html>
 3     <head>
 4         <meta charset="UTF-8">
 5         <title></title>
 6     </head>
 7     <body>
 8     </body>
 9     <script type="text/javascript">
10     
11     var number1 = 1, number2 = 2;
12     //数据类型，js 里面是弱类型 可以进行类型自动推断
13         数字类型1 Number
14         var value1 = 5;
15         console.log(typeof 5);
16         var value2 = 5.1;
17         console.log(typeof value2);
18         类型二：undefined
19         var value3;
20         console.log(typeof value3);
21         类型三:null
22         var value4 = null;
23         console.log(typeof value4);
24         类型四  string
25         var value5 = "我很好";
26         console.log(typeof value5);
27         类型五   bool 类型
28         console.log(typeof true);
29 
30    //对于 number 类型的补充
31     var  value1 = 0xFF;
32     console.log(value1);
33     var value2 = 012;
34     console.log(value2);    
35     </script>
36     
37 </html>