2020.7.12

一、今日学习内容

1、第三章综合实例：双色球

 1 import java.util.Random;
 2 import java.util.Arrays;
 3 public class Ball {
 4     public static void main(String[] args) {
 5         String[] pool= {"01","02","03","04","05","06","07","08","09","10","11","12",
 6                 "13","14","15","16","17","18","19","20","21","22","23","24","25","26",
 7                 "27","28","29","30","31","32","33"};
 8         boolean[] used=new boolean[pool.length];
 9         String[] balls=new String[6];
10         Random random=new Random();
11         int i;
12         int index=0;
13         while(true)
14         {
15             i=random.nextInt(pool.length);
16             if(used[i]) {
17                 continue;
18             }
19             balls[index++]=pool[i];
20             used[i]=true;
21             if(index==balls.length) break;
22         }
23         Arrays.sort(balls);
24         String[] newballs=new String[7];
25         for(int m=0;m<balls.length;m++) {
26             newballs[m]=balls[m];
27         }
28         newballs[newballs.length-1]=pool[random.nextInt(16)];
29         System.out.println("双色球："+Arrays.toString(newballs));
30     }
31 
32 }

输出结果：双色球：[01, 13, 16, 25, 29, 33, 14]

二、遇到的问题

有的问题想不到思路，不能有效运用学到的知识

三、明日计划

学习第四章内容：类