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Return an Iterator Object

Having a problem returing a Iterator object
Looking through an ArrayList then returing that Iterator object

public void addAllAtBottom (Filofax other)
    {
      Iterator e = other.iterator();
      while(e.hasNext())    <------------------ Problem is here it seems to skip this bit see below
      {
        Card card = (Card) e.next();
        list.add(card);
      }
    }

public Iterator iterator ()
    {
      Iterator e = list.iterator();

      while (e.hasNext()) {
       e.next();
      }
      return (Iterator)e;
    }

What i seem to be returning is an abstract Iterator ...whoosh over my head  i dont think the problem lies with the top method but within the e.HasNext of the iterator() method

Thank yo in advance!!
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dinger46
Asked:
dinger46
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1 Solution
 
Mayank SAssociate Director - Product EngineeringCommented:
Are these two methods inside the same class (Filofax)? Also, the while loop in your iterator () method seems to do nothing useful at all. Which class is Filofax extending?
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sciuriwareCommented:
You can't pass an abstract Iterator, because an Object derivate is by definition NOT abstract.
Your "return(Iterator)e;"   should be "return(e);" because you are referring to the same thing already.

The whole thing comes back to the "list.iterator()" method that will return you a real Iterator.

Is the "e.hasNext()" in the upper method in contradiction to the code in the lower method?

It's not clear to me how you connect the 2 methods here.
;JOOP!

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CEHJCommented:
If Filofax is a collection of Card as your code seems to suggest, it will already have an iterator() method. You can probably remove that one you have inserted into the calling class. If the calling class *is* Filofax then it will call the iterator() method you have installed and will produce the effect you mention below:

>>Problem is here it seems to skip this bit see below

Otherwise, one reason for that could be that there aren't any Card ;-)
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grim_toasterCommented:
Or alternatively change your iterator method to remove the calls next() calls.  Normal Iterators only allow you to iterate over each element once, therefore when you call next() on every item in the iterator, you are effectively going to the end, so anything that later uses it will say that there are no more elements

// change iterator() method...
public Iterator iterator ()
    {
      return list.iterator();
    }
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grim_toasterCommented:
Or as another approach, do not deal with the iterators, simply add all of the elements from one collection (presumption here) to the other, using Collection's addAll(Collection) method referencing the other objects list.
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CEHJCommented:
No need to hide the iterator() method that's probably *already* there ;-)
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Mayank SAssociate Director - Product EngineeringCommented:
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CEHJCommented:
Yes - thinking about that one - don't know whether I'd have much of use to contribute ;-)
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grim_toasterCommented:
Well at least you get asked!  Instead of those of us not on the top 15!  ;)
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CEHJCommented:
I'm sure he'd like to hear from you too! btw, dinger, the comment made at Date: 12/04/2003 03:26AM PST is one of the best yet.
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grim_toasterCommented:
Would that be my one or your one???
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Mayank SAssociate Director - Product EngineeringCommented:
grim_toaster, that question is for everyone to participate. I have also kept links to that question all 5 other sections, viz., Java, C, C++, Programming Languages and Visual Basic. Anyways, I'd better stop clogging this page :-)
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CEHJCommented:
>>Would that be my one or your one???

Well it can't be mine - unless we have different date views of this page ;-)
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