試題詳解

11. class PingPong2{

 12. synchronized void hit(long n){ 

13. for(int i=1; i<3; i++)

 14. System.out.print(n + "-" + i + " "); 

15. } 

16. } 

17. public dass Tester implements Runnable{ 

18. static PingPong2 pp2 = new PingPong2(); 

19. public static void main(String[] args){

 20. new Thread(new Tester()).start(); 

21. new Thread(new Tester()).start(); 

22. }

 23. public void run(){pp2.hit(Thread.currentThread.getId());} 

24. }

 Which statement is true?
(A) The output could be 5-1 6-1 6-2 5-2
(B) The output could be 6-1 6-2 5-1 5-2
(C) The output could be 6-1 5-2 6-2 5-1
(D) The output could be 6-1 6-2 5-1 7-1