Deletion from the beginning in a Linked List in JAVA

July 1, 2022

Java Program Deletion of a node from the beginning of Singly Linked List

Let us have a look at the Java Program for Deletion in a Singly Linked List at the beginning in Java. We will explore all possible methods of doing so below –

Deletion From a Singly Linked List
delete

Implementation

  • Deletion at the start is very simple
  • The head of the Linked list has to be moved to the next node
  • The current head memory will automatically be deleted by the garbage collector in Java since there will be no references to it
Singly Linked List Deletion in Java at Start

Code for Deletion at Beginning in Java

Let us have a look at the code below –

Linked List Deletion at the Start in Java
This method uses class instances to call functions.
Run 
import java.lang.*;

class LinkedList {
    Node head;

    // Node Class
    class Node{
        int data;
        Node next;

        Node(int x) // parameterized constructor
        {
            data = x;
            next = null;
        }
    }
    public void deleteStart()
    {
        if (head == null){
            System.out.println("List is empty, not possible to delete");
            return;
        }

        System.out.println("Deleted: " + head.data);
        // move head to next node
        head = head.next;
    }

    public Node insert(int data)
    {
        Node newNode = new Node(data);
        newNode.next = head;
        head = newNode;

        return head;
    }

    public void display()
    {
        Node node = head;
        //as linked list will end when Node reaches Null
        while(node!=null)
        {
            System.out.print(node.data + " ");
            node = node.next;
        }
        System.out.println("\n");
    }
}
public class Main
{
    public static void main(String args[])
    {
        LinkedList ll = new LinkedList();

        ll.insert(6);
        ll.insert(5);
        ll.insert(4);
        ll.insert(3);
        ll.insert(2);
        ll.insert(1);

        ll.display();

        ll.deleteStart();
        ll.display();

        ll.deleteStart();
        ll.deleteStart();
        ll.deleteStart();
        ll.display();
    }
}

Output

1 2 3 4 5 6 

Deleted: 1
2 3 4 5 6 

Deleted: 2
Deleted: 3
Deleted: 4
5 6
This method uses static methods to call functions.
Run 
import java.lang.*;

// Node Class
class Node {
    int data;
    Node next;

    Node(int x) // parameterized constructor
    {
        data = x;
        next = null;
    }
}

class Main
{
    public static Node deleteStart(Node head)
    {
        if (head == null){
            System.out.println("List is empty, not possible to delete");
            return head;
        }

        System.out.println("Deleted: " + head.data);
        // move head to next node
        head = head.next;

        return head;
    }

    public static Node insert(Node head, int data)
    {
        Node newNode = new Node(data);
        newNode.next = head;
        head = newNode;

        return head;
    }
    static void display(Node node) {

        //as linked list will end when Node is Null
        while (node != null) {
            System.out.print(node.data + " ");
            node = node.next;
        }
        System.out.println("\n");
    }
    

    public static void main(String args[])
    {
        Node head = null;

        head = insert(head, 6);
        head = insert(head, 5);
        head = insert(head, 4);
        head = insert(head, 3);
        head = insert(head, 2);
        head = insert(head, 1);
        display(head);

        head = deleteStart(head);
        display(head);

        head = deleteStart(head);
        head = deleteStart(head);
        head = deleteStart(head);
        display(head);

    }
}

Output

1 2 3 4 5 6 

Deleted: 1
2 3 4 5 6 

Deleted: 2
Deleted: 3
Deleted: 4
5 6

Singly Linked List

  • Introduction to Linked List in Data Structure
  • Linked List in – C | C++ | Java
  • Singly Linked List in – C | C++ | Java
  • Insertion in singly Linked List – C | C++ | Java
    • Insertion at beginning in singly Linked List  – C | C++ | Java
    • Insertion at nth position in singly Linked List  – C | C++ | Java
    • Insertion at end in singly Linked List  – C | C++ | Java
  • Deletion in singly Linked List  – C | C++ | Java
    • Deletion from beginning in singly linked list : C | C++ | Java
    • Deletion from nth position in singly linked list : C | C++ | Java
    • Deletion from end in singly linked list : C | C++ | Java
  • Reverse a linked list without changing links between nodes (Data reverse only) – C | C++ | Java
  • Linked List Insertion and Deletion – C | C++ | Java
  • Reverse a linked list by changing links between nodes – C | C++ | Java
  • Linked List insertion in the middle – C | C++ | Java
  • Print reverse of a linked list without actually reversing – C |C++ | Java
  • Search an element in a linked list – C | C++ | Java
  • Insertion in a Sorted Linked List – C | C++ | Java
  • Delete alternate nodes of a Linked List – C | C++ | Java
  • Find middle of the linked list – C | C++ | Java
  • Reverse a linked list in groups of given size – C | C++ | Java
  • Find kth node from end of the linked list – C | C++ | Java
  • Append the last n nodes of a linked list to the beginning of the list – C | C++ | Java
  • Check whether linked list is palindrome or not – C | C++ | Java
  • Fold a Linked List – C | C++ | Java
  • Insert at a given position – C | C++ | Java
  • Delete at a given position – C | C++ | Java

Singly Linked List

  • Introduction to Linked List in Data Structure
    Click Here
  • Linked List in –
    C | C++ | Java
  • Singly Linked List in –
    C | C++ | Java
  • Insertion in singly Linked List –
    C | C++ | Java
  • Insertion at beginning in singly Linked List  –
    C | C++ | Java
  • Insertion at nth position in singly Linked List  –
    C | C++ | Java
  • Insertion at end in singly Linked List  –
    C | C++ | Java
  • Deletion in singly Linked List  –
    C | C++ | Java
  • Deletion from beginning in singly linked list :
    C | C++ | Java
  • Deletion from nth position in singly linked list :
    C | C++ | Java
  • Deletion from end in singly linked list :
    C | C++ | Java
  • Linked List Insertion and Deletion –
    C | C++ | Java
  • Reverse a linked list without changing links between nodes (Data reverse only) –
    C | C++ | Java
  • Reverse a linked list by changing links between nodes –
    C | C++ | Java
  • Print reverse of a linked list without actually reversing –
    C |C++ | Java
  • Print reverse of a linked list without actually reversing –
    C |C++ | Java
  • Insertion in the middle Singly Linked List –
    C | C++ | Java
  • Insertion in a Sorted Linked List –
    C | C++ | Java
  • Delete alternate nodes of a Linked List –
    C | C++ | Java
  • Find middle of the linked list –
    C | C++ | Java
  • Reverse a linked list in groups of given size –
    C | C++ | Java
  • Find kth node from end of the linked list –
    C | C++ | Java
  • Append the last n nodes of a linked list to the beginning of the list –
    C | C++ | Java
  • Check whether linked list is palindrome or not –
    C | C++ | Java
  • Fold a Linked List –
    C | C++ | Java
  • Insert at given Position –
    C | C++ | Java
  • Deletion at given Position –
    C | C++ | Java