Why iterator

Question

Why do I need an Iterator (vector.iterator() or arraylist.iterator()) to iterate a collection object though I have all required methods to access the collection object.

Answer 1

aksarben wrote:
My point was that you can use for loops without iterators.Okay. I was more aiming at the OP and other newbies who might be reading. There used to be a lot of "for loop vs. iterator" questions here, as if it were either/or, when the real either or is get() vs. iterator. I assume the confusion came from the fact the one of the standard idioms for using an iterator used a while loop, while get() typically used a for loop.
The following are all equivalent:
// "old" idiom that newbies were most familiar with
List list = ...;
Iterator it = list.iterator();
while (it.hasNext()) {
  X x = (X)it.next();
  // do stuff
// "old" idiom that most experienced developers I've worked with used
List list = ...;
for (Iterator it = list.iterator(); it.hasNext();) {
  X x = (X)it.next();
  // do stuff
// "new" idiom which is just syntactic sugar for the above
List<X> list = ...;
for (X x : list) {
  // do stuff
}And the wrong ways to iterate, which are equivalent to each other, but not equivalent to the above are:
List<X> list = ...;
// wrong idiom which newbies are familiar with
for (int i = 0; i < list.length(); i++) {
  X x = list.get(i);
  // do stuff
// wrong idiom which is equivalent to the above, but not common
int i = 0;
while (i < list.length()) {
  X x = list.get(i);
  // do stuff
}