The peek() method of LinkedList retrieves but does not remove the first element in this linked list. It returns null if the list is empty.

Syntax

Object peek()

Parameters

It does not take any parameter

Return Value

It returns the first element in this linked-list

Program 1

import java.util.LinkedList;

public class LinkedListPeekExample {

        public static void main(String[] args) {

                LinkedList oddNumbers = new LinkedList();
                oddNumbers.add(5);
                oddNumbers.add(7);
                oddNumbers.add(9);
                oddNumbers.add(11);

                System.out.println("Linked List elements: " + oddNumbers);
                System.out.println("First element in this linked-list: "+oddNumbers.peek());
        }
}

Output

Linked List elements: [5, 7, 9, 11]
First element in this linked-list: 5

Program 2

import java.util.LinkedList;

public class LinkedListPeekExample {

        public static void main(String[] args) {

                LinkedList oddNumbers = new LinkedList();
                oddNumbers.add(5);
                oddNumbers.add(7);
                oddNumbers.add(9);
                oddNumbers.add(11);

                System.out.println("Linked List elements: " + oddNumbers);
                oddNumbers.clear();
                System.out.println("Linked List elements after clear() call: " + oddNumbers);
                System.out.println("First element in this linked-list: " + oddNumbers.peek());
        }
}

Output

Linked List elements: [5, 7, 9, 11]
Linked List elements after clear() call: []
First element in this linked-list: null