問題詳情

195.Given: 3. import java.util.*; 4. public class Mapit{ 5. public static void main(String[] args){ 6. Set<Integer> set = new HashSet<Integer>(); 7. Integer i1 = 45; 8. Integer i2 = 46; 9. set.add(i1); 10. set.add(i1); 11. set.add(i2); System.out.print(set.size() + " "); 12. set.remove(i1); System.out.print(set.size() + " "); 13. i2 = 47; 14. set.remove(i2); System.out.print(set.size() + " "); 15. } 16. }What is the result?
(A) 2 1 0
(B) 2 1 1
(C) 3 2 1
(D) 3 2 2
(E) Compilation fails.

參考答案