Diff between Enumeration and Iterator

[Dinesh Tahiliani]

Enumeration is to generate series of elements. or collection of elements / objects into a single object.

Iterator is take place on Enumeration. it is to clear and remove elements/objects from Enumeration obj.

Can anyone explain these lines in pratical way and in easy way.
I am finding difficult to undertand.
pls

[Gaurav Arora]

You are not allowed to remove elements from an Enumeration type in effect giving you a "view" only.

You can remove elements from an Iterator type thereby giving you "view & modify" behaviour.

This is from the javadocs :

NOTE: The functionality of this interface is duplicated by the Iterator interface. In addition, Iterator adds an optional remove operation, and has shorter method names. New implementations should consider using Iterator in preference to Enumeration.

[Dinesh Tahiliani]

One more question,

I have heard that List and ArrayList only takes objects, whenever you want to add.
But according to new concept of generics it also takes integer, when i am performing addition to list or arraylist.
Can you please shed some lights on this.
:roll:

[Nadeem Khan]

Actually when you add an integer to a List, its autowrapped as an Integer object and then added to the List.

[sitaram]

Hi,
non-syncronized classes are using only iterator.
syncronized classes are using only Enumeration.

Regards,
D.Sitaramayya.

[Mike Simmons]

Originally posted by d sitaramayya:
Hi,
non-syncronized classes are using only iterator.
syncronized classes are using only Enumeration.

Regards,
D.Sitaramayya.

That's not true. Vector is a synchronized class, and it has an iterator() method. It didn't originally have an iterator() method, but this was added back around JDK 1.2 when collections were brought into the main libraries. Now all collections have iterators, including Vector. Enumeration is just an older version of the same idea, with longer method names and one less method (remove()). So there's almost no reason to use Enumeration now.

[Dinesh Tahiliani]

Nad,

Actually when you add an integer to a List, its autowrapped as an Integer object and then added to the List

Can you explain me the above line with example. It would be really gerat for me.