試題詳解

第25題 Given: 1. class ClassA{ 2. public int numberOfInstances; 3. protected ClassA(int numberOfInstances){ 4. this.numberOfInstances = numberOfInstances; 5. } 6. } 7. class ExtendedA extends ClassA{ 8. private ExtendedA(int numberOfInstances){ 9. super(numberOfInstances); 10. } 11. public static void main(String[] args){ 12. ExtendedA ext = new ExtendedA(420); 13. System.out.print(ext.numberOfInstances); SCJP 6.0 認證教戰手冊 黃彬華著 碁峰出版 13 14. } 15. } What is the result?
(A) 420 is the output
(B) An exception is thrown at runtime.
(C) All constructors must be declared public.
(D) Constructors CANNOT use the private modifier.
(E) Constructors CANNOT use the protected modifier.