Link.java

// node created
    class Node{
        int data;
        Node next;
        Node(int data){
            this.data = data;
           next =  null;
        }
    }

public class Link{ 
    Node head;
    Node currentNode;
        Link(){
            head = null;
             
        }
    //add the element at the beginsning of the linked list
    void add_first(int data){
        // Node newnode = new Node(data);
        // newnode.next = head;
        // head = newnode;
        Node newnode = new Node(data);
        if (head == null) {
            head = newnode;
        }
        else{
        newnode.next = head;
        head = newnode;}
        
    }

    // add element at end
    // void add_last(int data){
    //     try {
    //     Node newnode = new Node(data);
    //     currentNode = head;
    //     if (currentNode == null) {
    //          currentNode = newnode;
            
    //     }
    //    else{
    //     while (currentNode != null) {
            
    //         currentNode = currentNode.next;
    //     } 
    //      currentNode  = newnode;
    // }
    //     } catch (Exception e) {
    //          System.out.println("error");
    //     }
// }

    // display linked list
    void display(){
        currentNode = head;
        if (currentNode == null) {
            System.out.println("List is empty.");
            return;
        }
       
        while (currentNode != null) {
            System.out.print(currentNode.data+"->");
            currentNode = currentNode.next;
        }
        System.out.println("null");
    }
 

 

    public static void main(String[] args) {
        Link l = new Link();
         
         l.display();
        l.add_first(7);
        l.add_first(6); 
        l.display();
        
       
       
         
    }
}