Doubt About Mock Exam Question?

[Gowher Naik]

Hi
i found this question in Kathy Sierra / Bert Bates monk exam.

1. import java.util.*;
2. public class Fruits {
3. public static void main(String [] args) {
4. Set c1 = new TreeSet();
5. Set o1 = new TreeSet();
6. bite(c1);
7. bite(o1);
8. }
9. // insert code here
10. }
11. class Citrus { }
12. class Orange extends Citrus { }

Which, inserted independently at line 9, will compile? (Choose all that apply.)

A). public static void bite(Set<?> s) { }
B). public static void bite(Set<Object> s) { }
C). public static void bite(Set<Citrus> s) { }
D). public static void bite(Set<? super Citrus> s) { }
E). public static void bite(Set<? super Orange> s) { }
F). public static void bite(Set<? extends Citrus> s) { }
G). Because of other errors in the code, none of these will compile.

Ans given in mock exam is this
A, E, and F are correct uses of generics with (bounded) wildcards.

But when i compile all options independently there is no compile time error for all options.There are compile warnings only for some options.

Please help.
Thanks

[Murali Mohan]

Yes Gowher!
You are right!
I made a similar mistake in the exam.

Every answer is compiling fine but some are giving warnings.

[nirumagics]

is it scjp1.4 or 1.5?

[wise owen]

SCJP1.5