Longer answer:

Using an iterator makes no assumption on the random-accessibility of your collection. Therefore you could replace the list in your code by another random Collection without a sweat.

Also, although the performance of an ArrayList is pretty good for random-access (get(i)), for a LinkedList, the get(i) method becomes relatively expensive.

One more thing: if you know the size doesn't in the middle of your iteration, it is not advised to re-call size() in each iteration! Iterators throw appropriate exceptions for concurrent modifications as well.

Yes because you are forcing the arrayList.get() to re-evaluation from index 0 thru to index "i" for each iteration.

This may not have a big impact with small arrays but for large arrays you are foring it to skip records every time, rather than work from the position you got to last time.