利用JavaScript生成随机数字！

jl29233zx 2021-09-02 原文

 1 <!DOCTYPE html>
 2 <html>
 3 <head>
 4     <title>1-99的随机数字</title>
 5     <script type="text/javascript">
 6     
 7         function selectFrom(lowerValue, upperValue) {
 8             var choices = upperValue - lowerValue + 1;
 9             return Math.floor(Math.random() * choices + lowerValue);
10         }
11         
12         var num = selectFrom(1, 99);
13         alert(num);   //number between 1 and 99
14         
15     </script>
16 </head>
17 <body>
18 
19 </body>
20 </html>

本例中使用了Math对象的Math.floor()方法以及random()方法！

那么我要生成1到99范围内9个不重复的数字，而且以数组形式输出呢？

 1 <!DOCTYPE html>
 2 <html>
 3 <head>
 4     <title>不重复的9个属于1-99的随机数字</title>
 5     <script type="text/javascript">
 6     
 7         function selectFrom(lowerValue, upperValue) {
 8             var choices = upperValue - lowerValue + 1;
 9             return Math.floor(Math.random() * choices + lowerValue);
10         }
11         
12         var num1 = selectFrom(1, 99);
13         var A = [] ;
14         A.push(num1) ;
15         for (var i = 1; i < 9; i++) {
16             var num2 = selectFrom(1, 99);
17             if (num2!==num1){
18                 A.push(num2) ; 
19             }
20         };
21         alert(A) ;
22         
23     </script>
24 </head>
25 <body>
26 
27 </body>
28 </html>