1 <!-- math.random 获取0-1的随机数
2 math.floor 向下取整
3 math.ceil 向上取整 -->
4 <!DOCTYPE html>
5 <html lang="en">
6 <head>
7 <meta charset="UTF-8">
8 <title>Document</title>
9 <script type="text/javascript">
10 var iPi = Math.PI;
11 alert(iPi);
12 var iNum = Math.random();
13 alert(iNum);
14 alert(Math.floor(5.6)); //弹出5
15 alert(Math.ceil(5.6)); //弹出6
16
17 console.log(iNum); // 调试代码的一种方式，浏览器检查元素，选择console菜单
18
19 // 生成10-20的随机整数
20 var iN01 = 10;
21 var iN02 = 20;
22 var arr2 = []
23 for(var i=0;i<40;i++)
24 {
25 var iNum02 = Math.floor((iN02 - iN01 +1)*Math.random()) + iN01;
26 arr2.push(iNum02);
27 }
28 console.log(arr2);
29 </script>
30 </head>
31 <body>
32
33 </body>
34 </html>
