remove from front:

    //works if length of list > 1
    head = head.next;
    head.prev = null;

  remove from back:

    //works if length of list > 1
    temp = head;
    //iterate to the end
    tail = temp.prev;
    temp.prev.next = null;

  remove from middle:

   temp = head;
   //iterate to index i
   temp.prev.next = temp.next;
   temp.next.prev = temp.prev;
   temp = null;
   
  ----------------------------
  Java API of LinkedList

    void addLast(element)
    void addFirst(element)
    AnyType getFirst()
    AnyType element() //does the same thing as getFirst()
    AnyType getLast()
    AnyType removeLast()
    AnyType removeFirst()
    AnyType remove() //does the same thing as removeFirst()

  ----------------------------
 
  Exercise: in a main method, create a LinkedList, fill it with
            50000 random Integers, then use a ListIterator to print
            them all out.	

  Solution:

  public static void main(String[] args){
	Random r = new Random();
		
	LinkedList<Integer> l = new LinkedList<Integer>();
	int i = 0;
	while(i < 50000){
		l.add(r.nextInt(50000));
		i++;
	}
		
	ListIterator<Integer> it = l.listIterator();
	while(it.hasNext()){
		System.out.println(it.next());
	}
		
  }