Linked Lists - Building Java Programs: A Back to Basics Approach - page 930

Table 16.1 Referring to Elements of a Sample List

Expression Type Description

Our variable that refers to the first node in the list list ListNode

data field of the first node ( 3 )

list.data int

next field of the first node list.next ListNode

data field of the second node ( 7 )

list.next.data int

next field of the second node list.next.next ListNode

data field of the third node ( 12 )

list.next.next.data int

next field of the third node list.next.next.next ListNode

Here is a complete program that includes all this code for constructing a three-
element list along with code that prints the list:

1 // Constructs and prints the list [3, 7, 12] by setting each
2 // field of each node.
3
4 public class Construct1 {
5 public static void main(String[] args) {
6 ListNode list = new ListNode();
7 list.data = 3;
8 list.next = new ListNode();
9 list.next.data = 7;
10 list.next.next = new ListNode();
11 list.next.next.data = 12;
12 list.next.next.next = null;
13 System.out.println(list.data + " " + list.next.data + " "
14 + list.next.next.data);
15 }
16 }

The program produces the following output:

3 7 12

Obviously, this program represents a very tedious way to manipulate a list. It's much
better to write code that involves loops to manipulate lists. But it takes a while to get used
to this idea, so we're first going to practice doing some raw list operations without a loop.

List Basics
Our previous version of the node class has just two fields:

public class ListNode {
public int data;
public ListNode next;

}