Collections

[Nikhil Jain]

Hi Guys,
Can you give me the answer of the following!!

Which of the following classes are concrete collection implementations provided by the Java Collections Framework?

1. HashSet
2. TreeMap
3. IMap
4. Map
5. Hash Table

Javacertificate.com says

The following classes are concrete implementations in the Java Collection Framework: HashSet, HashMap, ArrayList, TreeSet, TreeMap, LinkedList, Hashtable and Vector.

My Question is: It is generally said that MAP is not cosidered as a part of Collection frame work, then how come, the above answers includes MAP..

[Steve Morrow]

Map *is* part of the "Collections framework" introduced in Java 1.2. However, the Map interface does not extend the Collection interface.

Hope this helps.

[Serge Plourde]

If you take a look at the Java API Doc, you'll see that: TreeMap, IMap, Map,
and HashTable are not in the list of subinterfaces or implementing classes.

Interface Collection<E>

All Superinterfaces:
Iterable<E>

All Known Subinterfaces:
BeanContext, BeanContextServices, BlockingQueue<E>, List<E>, Queue<E>, Set<E>, SortedSet<E>

All Known Implementing Classes:
AbstractCollection, AbstractList, AbstractQueue, AbstractSequentialList, AbstractSet, ArrayBlockingQueue, ArrayList, AttributeList, BeanContextServicesSupport, BeanContextSupport, ConcurrentLinkedQueue, CopyOnWriteArrayList, CopyOnWriteArraySet, DelayQueue, EnumSet, HashSet, JobStateReasons, LinkedBlockingQueue, LinkedHashSet, LinkedList, PriorityBlockingQueue, PriorityQueue, RoleList, RoleUnresolvedList, Stack, SynchronousQueue, TreeSet, Vector