Linked Data Structures - Java - page 796

Display 15.25 A Doubly Linked List with an Iterator (part 3 of 3)

86 private TwoWayNode head;

87 public DoublyLinkedIterator iterator( )

88 {

89 return new DoublyLinkedIterator( );

90 }

91 public DoublyLinkedList( )

92 {

93 head = null ;

94 }

95 /**
96 The added node will be the first node in the list.
97 */
98 public void addToStart(String itemName)
99 {
100 TwoWayNode newHead = new TwoWayNode(itemName, null , head);
101 if (head != null )
102 {
103 head.previous = newHead;
104 }
105 head = newHead;
106 }
< The methods hasNext , peek , clear , and isEmpty are identical
to those in Display 15.17. Other methods would also normally
be defined here, such as deleteHeadNode , size , outputList ,
equals , clone , find , or contains . They have been left off to
simplify the example.>
107 } // DoublyLinkedList

Display 15.26 Using a Doubly Linked List with an Iterator (part 1 of 2)

1 public class DoublyLinkedListDemo
2{
3 public static void main(String[] args)

4 {

5 DoublyLinkedList list = new DoublyLinkedList( );

6 DoublyLinkedList.DoublyLinkedIterator i = list.iterator( );

7 list.addToStart("shoes");

8 list.addToStart("orange juice");

9 list.addToStart("coat");