Add elements at beginning and end of LinkedList in Java

Elements can be added at the beginning of a LinkedList by using the method java.util.LinkedList.addFirst(). This method has a single argument i.e. the element that is to be added at the beginning of the LinkedList.

Elements can be added at the end of a LinkedList by using the method java.util.LinkedList.addLast(). This method has a single argument i.e. the element that is to be added at the end of the LinkedList.

A program that demonstrates this is given as follows −

Example

 Live Demo

import java.util.LinkedList;
public class Demo {
   public static void main(String[] args) {
      LinkedList<String> l = new LinkedList<String>();
      l.add("Apple");
      l.add("Mango");
      l.add("Pear");
      System.out.println("The LinkedList is: " + l);
      l.addFirst("Orange");
      l.addLast("Guava");
      System.out.println("The LinkedList is: " + l);
   }
}

Output

The LinkedList is: [Apple, Mango, Pear]
The LinkedList is: [Orange, Apple, Mango, Pear, Guava]

Now let us understand the above program.

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

LinkedList<String> l = new LinkedList<String>();
l.add("Apple");
l.add("Mango");
l.add("Pear");
System.out.println("The LinkedList is: " + l);

The methods LinkedList.addFirst() and LinkedList.addLast() is used to insert the elements “Orange” and “Guava” at the beginning and end of the Linked List respectively. Then the LinkedList is again displayed. A code snippet which demonstrates this is as follows −

l.addFirst("Orange");
l.addLast("Guava");
System.out.println("The LinkedList is: " + l);

Karthikeya Boyini

Published on 30-Jan-2019 12:24:45