Linked Data Structures - Java - page 781

Display 15.17 A Linked List with an Iterator (part 3 of 3)

61 else if (position == null || previous == null )

62 // list is empty or position is head node

63 LinkedList2.this.addtoStart(newData);

64 else

65 { // previous and position are consecutive nodes

66 Node temp = new Node(newData, position)

67 previous.link = temp;

68 previous = temp;

69 }

70 }

71 /**

72 Changes the String in the node at location position.

73 Throws an IllegalStateException if position is not at a node,

74 */

75 public void changeHere(String newData)

< The rest of the method changeHere is Self-Test Exercise 13. >

76 /**

77 Deletes the node at location position and

78 moves position to the "next" node.

79 Throws an IllegalStateException if the list is empty.

80 */

81 public void delete( )

82 {

83 if (position == null )

84 throw new IllegalStateException( );

85 else if (previous == null )

86 { // remove node at head

87 head = head.link;

88 position = head;

89 }

90 else // previous and position are consecutive nodes

91 {

92 previous.link = position.link;

93 position = position.link;

94 }

95 }

If list is an object of the
class LinkedList2 , then
list.iterator( )
returns an iterator for list.

96 private Node head;

97 public List2Iterator iterator( )
98 {
99 return new List2Iterator( );
100 }
< The other methods and constructors are identical to those in Displays 15.7 and 15.11. >
101 }