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K &B Erratum? Regarding generics

babu sharath
Ranch Hand

Joined: Jul 06, 2006
Posts: 42
Given code :
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.

Answer is : A,E,F
I know A is correct .
why E & F are correct ??


(edited topic to indicate K&B 5.0 erratum)
[ July 25, 2006: Message edited by: Barry Gaunt ]
Barry Gaunt
Ranch Hand

Joined: Aug 03, 2002
Posts: 7729
Use this:


Check out this past topic (about half way down)

Hopefully the K&B errata includes this by now
[ July 25, 2006: Message edited by: Barry Gaunt ]

Ask a Meaningful Question and HowToAskQuestionsOnJavaRanch
Getting someone to think and try something out is much more useful than just telling them the answer.
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: K &B Erratum? Regarding generics