Iterate through a LinkedList in reverse direction using a ListIterator in Java

Java 8 Object Oriented Programming Programming

A ListIterator can be used to traverse the elements in the forward direction as well as the reverse direction in a LinkedList. The method hasPrevious( ) in ListIterator returns true if there are more elements in the LinkedList while traversing in the reverse direction and false otherwise. The method previous( ) returns the previous element in the LinkedList and reduces the cursor position backward.

A program that demonstrates this is given as follows.

Example

Live Demo

import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
public class Demo {
   public static void main(String[] args) {
      List l = new LinkedList();
      l.add("John");
      l.add("Sara");
      l.add("Susan");
      l.add("Betty");
      l.add("Nathan");
      ListIterator i = l.listIterator(l.size());
      System.out.println("The LinkedList elements in the reverse direction are: ");
      while (i.hasPrevious()) {
         System.out.println(i.previous());
      }
   }
}

Output

The output of the above program is as follows

The LinkedList elements in the reverse direction are:
Nathan
Betty
Susan
Sara
John

Now let us understand the above program.

The LinkedList is created and LinkedList.add() is used to add the elements to the LinkedList. A code snippet which demonstrates this is as follows

List l = new LinkedList();
l.add("John");
l.add("Sara");
l.add("Susan");
l.add("Betty");
l.add("Nathan");

Then the ListIterator interface is used to display the LinkedList elements in the reverse direction. A code snippet which demonstrates this is as follows

ListIterator i = l.listIterator(l.size());
System.out.println("The LinkedList elements in the reverse direction are: ");
while (i.hasPrevious()) {
   System.out.println(i.previous());
}

Ankith Reddy

Published on 18-Jan-2019 05:45:17

Previous Page Print Page