Description

To delete a node from beginning of the singly linked list - 
Case 1: check if list is empty 
	Show message that list is empty.
Case 2: When list has few elements
	step 1 : Assign the address of first node to temporary variable.
	step 2 : Make second node as first node by Assigning the address of second node to head.
	step 3 : Free the memory occupied by first node
	
Note: Here head contains the address of first node

C/C++

/* C program of Program To Delete a Node from beginning in singly linked list */
//Save it as delete_node_beginning_singly_linked_list.c

#include<stdio.h>
#include<malloc.h>
struct node *create(int);
void display(struct node *);
struct node *delete_beg(struct node *);

//Declaring node
struct node{
    int data;
    struct node *next;
};

int main(){
    int n;
    struct node *head;
    printf("Enter number of nodes : ");
    scanf("%d",&n);
    
    //Calling function to create node
    head=create(n);
    
    //Calling function to display list
    display(head);
    
    //Code to delete a node from beginning
    head=delete_beg(head);
    printf("\nThe linked list after deletion of node from beginning - \n");
    
    //Calling function to display list after deletion of node from beginning
    display(head);

    return 0;
}

struct node *create(int n){
    int i;
    struct node *head=NULL;
    struct node *ptr,*newNode;

    for(i=0;i<n;i++){
        
        //Creating a new node
        newNode=(struct node*)malloc(sizeof(struct node*));
        
        //Assigning data to newly created node
        printf("Enter the value of %d node : ",i+1);
        scanf("%d",&newNode->data);
        newNode->next=NULL;
        
        /*If list is empty assign the address of newly created node to head*/
        if(head==NULL){
            head=newNode;
        }else{
            
            /* If list already have few elements then loop through
            list and add newly created node after given node*/
            ptr=head;
            while(ptr->next!=NULL){
                ptr=ptr->next;
            }
            ptr->next=newNode;
        }
    }
    return head;
}

void display(struct node *head){
    struct node *ptr;
    
    //If list is empty
    if(head==NULL){
        printf("The linked list is empty");
    }else{
        
        /*If list has elements then loop through the loop and
        print elements one by one in sequential manner*/
        ptr=head;
        while(ptr!=NULL){
            printf("The node value = %d and their address = %u\n",ptr->data,ptr);
            ptr=ptr->next;
        }
    }
}

//Function to delete a node from beginning
struct node *delete_beg(struct node *head){
    
    //No node is available to delete
    if(head==NULL){
        printf("Link list is empty..No node to delete!!");
    }else{
        
        //Assigning the address first node to temporary variable
        struct node *ptr=head;
        head=ptr->next;
        
        //Free the memory after deletion of node
        free(ptr);
    }
    return head;
}

Input:
Enter number of nodes : 5
Enter the value of 1 node : 1
Enter the value of 2 node : 2
Enter the value of 3 node : 3
Enter the value of 4 node : 4
Enter the value of 5 node : 5
The node value = 1 and their address = 200024
The node value = 2 and their address = 200056
The node value = 3 and their address = 200072
The node value = 4 and their address = 200088
The node value = 5 and their address = 200104

Output:
The linked list after deletion of node from beginning -
The node value = 2 and their address = 200056
The node value = 3 and their address = 200072
The node value = 4 and their address = 200088
The node value = 5 and their address = 200104

Java

/* Java program of Program To Delete a Node from beginning in singly linked list */
//Save it as DeleteNodeBeginningSinglyLinkedList.java

import java.io.*;
import java.util.Scanner;

public class DeleteNodeBeginningSinglyLinkedList {
    
    // Declaring node
    class Node {
        int data;
        Node next;

        public Node(int data) {
            this.data = data;
            
            // Assigning null value to the next field
            this.next = null;
        }
    }

    public Node head = null;
    
    // Function to add node
    public void addNode(int data) {
        
        // Creating a new node
        Node newNode = new Node(data);
        
        /* If list is empty assign the address of newly created node to head */
        if (head == null) {
            head = newNode;
        } else {
            
            /* If list already have few elements then loop through list and */
            Node ptr = head;
            while (ptr.next != null) {
                ptr = ptr.next;
            }
            ptr.next = newNode;
        }
    }

    public void display() {
        Node ptr = head;
        
        // If list is empty
        if (ptr == null) {
            System.out.println("The list is empty");
            return;
        }
        System.out.println("The nodes of lists are : ");

        
        /* If list has elements then loop through the loop and print elements one by one
           in sequential manner*/
         
        while (ptr != null) {
            System.out.print(ptr.data + " ");
            ptr = ptr.next;
        }
    }

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        DeleteNodeBeginningSinglyLinkedList list = new DeleteNodeBeginningSinglyLinkedList();

        System.out.println("Enter number of node you want to enter : ");
        int n = scanner.nextInt();

        for (int i = 0; i < n; i++) {
            System.out.println("Enter value of " + (i + 1) + " node : ");
            int val = scanner.nextInt();
            list.addNode(val);
        }
        
        // Calling function to display list
        list.display();

        list.delete_beg();
        
        // Calling function to display list after deletion of node from beginning
        System.out.println("\nAfter deletion of node from beginning - ");
        list.display();
    }
    
    //Function to delete node
    private void delete_beg() {
        
        //No node is available to delete
        if(head==null) {
            System.out.println("Link list is empty..No node to delete!!");
        }else {
            
            //Assigning the address first node to temporary variable
            Node ptr=head;
            head=ptr.next;
        }
    }
}

Input:
Enter number of node you want to enter : 
5
Enter value of 1 node : 
1
Enter value of 2 node : 
2
Enter value of 3 node : 
3
Enter value of 4 node : 
4
Enter value of 5 node : 
5
The nodes of lists are : 
1 2 3 4 5 

Output:
After deletion of node from beginning - 
The nodes of lists are : 
2 3 4 5

Related Programs