Java LinkedList Example
In this section we will discuss about the own implementation of Linked List in Java.
Linked List is a part of Data Structure. In Linked List nodes are connected by a link this link is referred to as one node contains the reference of next node. In this tutorial we will learn this by a simple example. In this example we will display an original list and then display its reverse order.
Example
Here I am going to give a simple example which demonstrate how nodes are linked to each other and how can we displayed in their order as well as in its reverse order. In this example I have created Java classes. The Java class Link instantiates a reference variable next which will be used for linking the next value in the list. Then created a class named LinkList where written methods for printing the list value in its order and its reverse order. Then created a main class where created the list values and called methods for displaying list values.
Source Code
class Link { Link next; String num; Link (String num ) { this.num = num; } public String toString() { return num; } }// close Link class class LinkList { Link first; public void print(Link node) { System.out.print (node); if (node.next!=null) { System.out.print (" -> "); print(node.next); } } public void reverseList() { Link node3 = first; Link node2 = null; Link node1 = null; while (node3!= null) { node1 = node2; node2 = node3; node3 = node2.next; node2.next = node1; } first = node2; } }// close LinkList public class JavaSinglyLinkList { public static void main (String args[]) { Link l1 = new Link("1"); Link l2 = new Link("2"); Link l3 = new Link("3"); Link l4 = new Link("4"); Link l5 = new Link("5"); l1.next = l2; l2.next = l3; l3.next = l4; l4.next = l5; LinkList LL = new LinkList(); LL.first = l1; System.out.println ("\nCurrent list"); LL.print(LL.first); LL.reverseList(); System.out.println(); System.out.println ("\nList in reverse order"); LL.print(LL.first); System.out.println(); } }
Output
When you will execute the JavaSinglyLinkList.java then the output will be as follows :