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 num = 1.4;
10 console.log(Math.abs(num)); //取绝对值：1.4
11 console.log(Math.floor(num)); //向下取整：1
12 console.log(Math.ceil(num)); //向上取整：2
13 console.log(Math.round(num)); //四舍五入取整，正数四舍五入，负数五舍六入：1
14 console.log(Math.random()); //随机数0-1
15 console.log(Math.random()*100); //随机数0-100
16 console.log(Math.floor(Math.random()*100)); //0-100的随机数向下取整
17
18 var num1 = -0.6;
19 console.log(Math.abs(num1)); //0.6
20 console.log(Math.floor(num1)); //-1
21 console.log(Math.ceil(num1)); //0
22 console.log(Math.round(num1)); //-1
23 </script>
24 </body>
25 </html>