Linked Lists - Building Java Programs: A Back to Basics Approach - page 952

33 String result = "[" + front.data;
34 ListNode current = front.next;
35 while (current != null) {
36 result += ", " + current.data;
37 current = current.next;
38 }
39 result += "]";
40 return result;
41 }
42 }
43
44 // post: returns the position of the first occurrence of the
45 // given value (-1 if not found)
46 public int indexOf( int value) {
47 int index = 0;
48 ListNode current = front;
49 while (current != null) {
50 if (current.data == value) {
51 return index;
52 }
53 index++;
54 current = current.next;
55 }
56 return -1;
57 }
58
59 // post: appends the given value to the end of the list
60 public void add(int value) {
61 if (front == null) {
62 front = new ListNode(value);
63 } else {
64 ListNode current = front;
65 while (current.next != null) {
66 current = current.next;
67 }
68 current.next = new ListNode(value);
69 }
70 }
71
72 // pre: 0 <= index <= size()
73 // post: inserts the given value at the given index
74 public void add( int index, int value) {
75 if (index == 0) {
76 front = new ListNode(value, front);