Java 实例 - 集合打乱顺序


以下实例演示了如何使用 Collections 类 Collections.shuffle() 方法来打乱集合元素的顺序:

  1. /*
  2. author by shouce.ren
  3. Main.java
  4. */
  5.  
  6. import java.util.*;
  7.  
  8. public class Main {
  9. public static void main(String[] args) {
  10. List<Integer> list = new ArrayList<Integer>();
  11. for (int i = 0; i < 10; i++)
  12. list.add(new Integer(i));
  13. System.out.println("打乱前:");
  14. System.out.println(list);
  15.  
  16. for (int i = 1; i < 6; i++) {
  17. System.out.println("第" + i + "次打乱:");
  18. Collections.shuffle(list);
  19. System.out.println(list);
  20. }
  21. }
  22. }

以上代码运行输出结果为:

  1. 打乱前:
  2. [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  3. 1次打乱:
  4. [2, 0, 5, 1, 4, 9, 7, 6, 3, 8]
  5. 2次打乱:
  6. [2, 6, 4, 8, 5, 7, 9, 1, 0, 3]
  7. 3次打乱:
  8. [6, 5, 1, 0, 3, 7, 2, 4, 9, 8]
  9. 4次打乱:
  10. [1, 3, 8, 4, 7, 2, 0, 6, 5, 9]
  11. 5次打乱:
  12. [3, 0, 7, 9, 5, 8, 4, 2, 1, 6]