9. The Iterator interface

• 
  public interface Iterator<E> {
      boolean hasNext(); // returns true if the iteration has more elements
      E next();          // returns the next element in the iteration
      void remove();     // removes the last element that was returned by next()
  }
  
  

  Why use iterators instead of the for-each construct?

  • To remove selective elements during iteration. The for-each construct hides the iterator, so you cannot remove elements.

  • Iterate over multiple collections in parallel.