試題詳解

11. public class Person{ 

12. private String name； 

13. public Person(String name){ 

14. this.name = name； 

 15. } 

16. public boolean equals(Object o){ 

17. if(!(o instanceof Person)) return false； 

18. Person p = (Person)o； 

19. return p.name.equals(this.name)； 

20. }

 21. } Which statement is true?
(A) Compilation fails because the hashCode method is not overridden.
(B) A HashSet could contain multiple Person objects with the same name.
(C) All Person objects will have the same hash code because the hashCode method is not overridden.
(D) If a HashSet contains more than one Person object with name="Fred", then removing another Person, also with name="Fred", will remove them all.