An Introduction to Data Structures - Java Concepts - page 926

74 /**
75 Constructs an iterator that points to the front
76 of the linked list.
77 */
78 public LinkedListIterator()
79 {
80 position = null ;
81 previous = null ;
82 }
83
84 /**
85 Moves the iterator past the next element.
86 @return the traversed element
87 */
88 public Object next()
89 {
90 if (!hasNext())
91 throw new NoSuchElementException();
92 previous = position; // Remember for remove
93
94 if (position == null )
95 position = first;
96 else
97 position = position.next;
98
99 return position.data;
100 }
101
102 /**
103 Tests if there is an element after the iterator
104 position.
105 @return true if there is an element
after the iterator
106 position
107 */
108 public boolean hasNext()
109 {
110 if (position == null )
111 return first != null ;
112 else
113 return position.next != null ;
114 }