SE450: Inner Classes: Local Inner Classes [12/22]

Inner classes can be created in code blocks, such as method bodies. These classes are not members of the class, so they can't be private, protected, public, static or final. They have access to the final variables of the code block as well as other members of the class, static and not-static. (think scope as to why this is the case)

Consider the Iterator interface (we talked about it last week and will look at it again tonight).

public interface Iterator {
  public boolean hasNext();
  public Object next();
  public void remove();
}

public static Iterator walthThrough(final Object[] objs) {

  // local inner class
  class Iter implements Iterator {
    private int pos = 0;
    public boolean hasNext() {
      return (pos < objs.length);
    }
    public Object next() throws NoSuchElementException {
      if(pos < objs.length)
        throw new NoSuchElementException();
      return objs[pos++];
    }
  }

  return new Iter();
}