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Collections and Generics

 
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Hi All,
Can you please tell me the Answer for this following qusetion.I think
A,B,C,D,E,F are right.Is it correct?.

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
 
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All are correct Answers but i am not getting why all are correct ,can anyone explain please......
 
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Originally posted by raj malhotra:
All are correct Answers but i am not getting why all are correct ,can anyone explain please......

Since o1 and c1 have no element type information. As result, the compiler assumes that the programmer knows what he does, and issues only a warning (except for case A, where any list is valid).
 
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