Deletion in Singly Linked List

Last Updated: 06 October, 2024 🕓 5 Mins

In this Linked List tutorial, we will see all about the delete operation in a single linked list. In the delete operation, we will remove an existing node from the linked list from any position.

In a Singly Linked List, we can delete a node at the following positions:

From the beginning of the linked list.
From middle of the linked list.
From the end of the linked list.

Create a node class

  public class Node {
    public int data;
    public Node next;
  
    // Constructor
    public Node(int data) {
      this.data = data;
      this.next = null;
    }
  }

1. Delete a node from the beginning of the linked list

In the below given example we will see how to delete an existing node from the beginning or front the linked list.

  
  // Java program to delete a node from the beginning of the linked list
  public class DeleteNodeAtBignningInSLL {
    // Method to delete the head node
    static Node deleteHead(Node head) {
      // Before deleting a node just make sure list should not be empty
      if (head == null) {
        System.out.println("List is empty");
        return null;
      }
      
      // Change the head pointer to the next node
      // and free the original head
      Node temp = head;
      head = head.next;
      
      // Free the original head (handled by garbage collector)
      temp = null;
      
      // Return the new head
      return head;
    }
    
    // Method to print the doubly linked list
    public static void printList(Node head) {
      while (head != null) {
        System.out.print(head.data + " -> ");
        head = head.next;
      }
      System.out.println("null");
    }
    
    public static void main(String[] args) {
      // Create nodes
      Node head = new Node(10);
      head.next = new Node(20);
      head.next.next = new Node(30);
      head.next.next.next = new Node(40);
      
      System.out.println("Original Linked List data: ");
      printList(head);
      
      // Deleting the head node
      head = deleteHead(head);
      System.out.println("After deleting head, Linked List data: ");
      printList(head);
    }
  }

Output

Original Linked List data:
10 -> 20 -> 30 -> 40 -> null
After deleting head, Linked List data:
20 -> 30 -> 40 -> null

2. Delete a node from the middle of the linked list

In the below given example we will see how to delete an existing node from the any position of the linked list.

  
  // Java program to delete a node from the linked list at the given position
  public class DeleteNodeAtMiddleInSLL {
  
    // Method to delete a node at a given position
    public static Node deleteNode(Node head, int position) {
      // Before deleting a node just make sure list should not be an empty
      if (head == null) {
        System.out.println("List is empty");
        return head;
      }
  
      Node temp = head;
      Node prev = null;
  
      // Case 1: Head is to be deleted
      if (position == 1) {
        head = temp.next;
        return head;
      }
  
      // Case 2: Node to be deleted is in middle
      // Traverse till given position
      for (int i = 1; temp != null && i < position; i++) {
        prev = temp;
        temp = temp.next;
      }
  
      // If given position is found, delete node
      if (temp != null) {
        prev.next = temp.next;
      } else {
        System.out.println("Data not present in the list.");
      }
  
      return head;
    }
  
    // Method to print a list
    public static void printList(Node head) {
      while (head != null) {
        System.out.print(head.data + " -> ");
        head = head.next;
      }
      System.out.println("null");
    }
  
    public static void main(String[] args) {
      // Create nodes
      Node head = new Node(10);
      head.next = new Node(20);
      head.next.next = new Node(30);
      head.next.next.next = new Node(40);
      head.next.next.next.next = new Node(50);
  
      System.out.println("Original Linked List data:");
      printList(head);
  
      // Deleting node at position 3
      head = deleteNode(head, 3);
  
      // Print list after deletion
      System.out.print("After deletion, Linked List data:\n");
      printList(head);
    }
  }

Output

Original Linked List data:
10 -> 20 -> 30 -> 40 -> 50 -> null
After deletion, Linked List data:
10 -> 20 -> 40 -> 50 -> null

3. Delete a node from the end of the linked list

In the below given example we will see how to delete an existing node from the end or last the linked list.

  
  // Java program to delete the end or last node of linked list
  public class DeleteNodeAtEndInSLL {
    // Method to remove the last node from the linked list
    static Node removeLastNode(Node head) {
      
      // Before deleting a node just make sure list should not be empty
      if (head == null) {
        System.out.println("List is empty");
        return null;
      }
      
      // If the list has only one node, delete it and return null
      if (head.next == null) {
        return null;
      }
      
      // Find the second last node
      Node secondLast = head;
      while (secondLast.next.next != null) {
        secondLast = secondLast.next;
      }
      
      // Delete the last node
      secondLast.next = null;
      
      return head;
    }
    
    // Method to print the list
    public static void printList(Node head) {
      while (head != null) {
        System.out.print(head.data + " -> ");
        head = head.next;
      }
      System.out.println("null");
    }
    
    public static void main(String[] args) {
      // Create nodes
      Node head = new Node(10);
      head.next = new Node(20);
      head.next.next = new Node(30);
      head.next.next.next = new Node(40);
      
      System.out.println("Original Linked List data: ");
      printList(head);
      
      // Removing the last node from the list
      head = removeLastNode(head);
      
      System.out.println("After removing last node, Linked List data: ");
      printList(head);
    }
  }

Output

Original Linked List data:
10 -> 20 -> 30 -> 40 -> null
After removing last node, Linked List data:
10 -> 20 -> 30 -> null