LinkedList removeFirst() method with example in java

The removeFirst() method of LinkedList retrieves and removes the first element in this list. It throws a NoSuchElementException exception if this list is empty.

Syntax

Object removeFirst()

Parameters

It doesn't take any parameter

Return Value

the removed element in this list

Exception

 It throws NoSuchElementException exception if this list is empty.

Program 1

import java.util.LinkedList;

public class LinkedListRemoveFirstExample {

	public static void main(String[] args) {

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

		System.out.println("Linked List elements: " + oddNumbers);
		oddNumbers.removeFirst();
		System.out.println("Linked List after removing first element: " + oddNumbers);
	}
}

Output

Linked List elements: [5, 7, 9, 11]
Linked List after removing first element: [7, 9, 11]

Program 2

import java.util.LinkedList;

public class LinkedListRemoveFirstExample {

	public static void main(String[] args) {

		LinkedList<Integer> 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);
		oddNumbers.removeFirst();// throws NoSuchElementException as linked-list is null
	}
}

Output

Exception in thread "main" Linked List elements: [5, 7, 9, 11]
Linked List elements after clear() call: []
java.util.NoSuchElementException
	at java.util.LinkedList.removeFirst(LinkedList.java:270)
	at LinkedListRemoveFirstExample.main(LinkedListRemoveFirstExample.java:18)