countNodes.java

public class countNodes 
{    
    class Node
    {    
        int data;    
        Node next;    
            
        public Node(int data) 
        {    
            this.data = data;    
            this.next = null;    
        }    
    }       
    public Node head = null;    
    public Node tail = null;    
    public void addNode(int data) 
    {     
        Node newNode = new Node(data);    
        if(head == null) 
        {        
            head = newNode;    
            tail = newNode;    
        }    
        else 
        {       
            tail.next = newNode;       
            tail = newNode;    
        }    
    }      
    public int countNodes() 
    {    
        int count = 0;     
        Node current = head;    
            
        while(current != null) 
        {     
            count++;    
            current = current.next;    
        }    
        return count;    
    }        
    public void display() 
    {       
        Node current = head;    
        if(head == null) 
        {    
            System.out.println("List is empty");    
            return;    
        }    
        System.out.println("Nodes of singly linked list: ");    
        while(current != null) 
        {       
            System.out.print(current.data + " ");    
            current = current.next;    
        }    
        System.out.println();    
    }    
        
    public static void main(String[] args) 
    {    
            
        countNodes sList = new countNodes();      
        sList.addNode(1);    
        sList.addNode(2);    
        sList.addNode(3);    
        sList.addNode(4);     
        sList.display();      
        System.out.println("Count of nodes present in the list: " + sList.countNodes());    
    }    
}