1 <!doctype html>
2 <html lang="en">
3 <head>
4 <meta charset="UTF-8">
5 <title>Document</title>
6 </head>
7 <body>
8 <script>
9 var a1 = {
10 c:1,
11 d:2
12 }
13 var a2 = [1,2,3];
14 var a3 = 2;
15 var a4 = "wwww";
16 var b1 = Object.prototype.toString.call(a1);
17 var b2 = Object.prototype.toString.call(a2);
18 var b3 = Object.prototype.toString.call(a3);
19 var b4 = Object.prototype.toString.call(a4);
20 var b5 = Object.prototype.toString.call(null);
21 var b6 = Object.prototype.toString.call(NaN);
22 console.log(b1);
23 console.log(b2);
24 console.log(b3);
25 console.log(b4);
26 console.log(b5);
27 console.log(b6);
28 console.log(NaN)
29 </script>
30 </body>
31 </html>