Iteratoren (II)

,,klassisch`` (sichtbarer Iterator):

static Integer product (List<Integer> l) {
  Iterator<Integer> it = l.iterator ();
  Integer p = 1; // auto-boxing
  while (it.hasNext ()) { p *= it.next (); }
  return p;
}

,,modern``: enhanced for-loop (impliziter Iterator):

static Integer product (List<Integer> c) {
  Integer p = 1;
  for (Integer x : c) { p *= x; }
  return p;
}