第28題

Given:
1. class X{
2. X(){System.out.print(1);}
3. X(int x){
4. this();
5. System.out.print(2);
6. }
7. }
8. public class Y extends X{
9. Y(){
10. super(6);
11. System.out.print(3);
12. }
13. Y(int y){
14. this();
15. System.out.println(4);
16. }
17. public static void main(String[] a){new Y(5);}
18. }
What is the result?
A. 13
B. 134
C. 1234
D. 2134
E. 2143
F. 4321

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答案：C
參考：6-5 繼承

17. public static void main(String[] a){new Y(5);}
>>8. public class Y extends X{
>>13. Y(int y){
>>>>9. Y(){
>>>>10. super(6);
>>>>>> 3. X(int x){
>>>>>> 4. this();
>>>>>>>> 2. X(){System.out.print(1);} //output 1
>>>>>>>> 5. System.out.print(2); //output 2
>>>>>>>> 11. System.out.print(3); //output 3
>>>>>>>> 15. System.out.println(4); //output 4