Changing data in previous element of ArrayList

Question

I'm iterating through an array list which contains several data elements in each array, one of which is an account numbers which are sorted. If an account number is duplicated, I want to change data in both entries in the ArrayList.
for (ListIterator iter = myList.listIterator(); iter.hasNext();)
                  MyList vantageList = (MyList) iter.next();
      if ( iter.hasPrevious)
         MyList previousElement =  (MyList)iter.previous();
          previousElement.setAccountNumber(12345);
      if (imageLitr.hasNext)
         MyList nextElement = (MyList)imageLitr.next();
        nextElement.setAccountNumber(12345);
}but the previousElement is not being updated with 12345, and I'm not sure why.
thanks
Edited by: drakester on Oct 10, 2007 11:53 AM

Answer 1

drakester wrote:
This is the code I have and it's not updating the previous element in the list with "D" and I have no idea why?That code looks correct enough. There are a couple things you're doing which are unnecessary: You don't need to check for a null previousAccountNumber - assuming accountNumber isn't null (which it isn't or you'd have another problem), a non-null string is never equal to a null one. And there's no need to check for iter.hasPrevious nor hasNext, because if you have found a duplicate, obviously there is a previous item, it's the duplicate one you already saw. So you move to that item and mark it. Then obviously there's a next item too, because you just moved back one item and need to move forward again to the current item you were just working on.
Anyway, it looks like it should work, so I'd have to guess that:
1) You're not actually executing this code
2) The list isn't sorted when you execute this code
3) You're seeing the problem because of something else - not looking at this updated list, or something else updated it after this code executed and you're seeing the effects of that update, not this one.
4) setToD doesn't do anything
5) Something else