simple LL cpp

#include <iostream>

using namespace std;

class node{

protected:
    int element;
    node* link;

public:
    //constructor that accepts only element
    node(int element) {
        this->element = element;
        this->link = NULL;
    }

    //constructor that accepts both link and element
    node(int element, node* link){
        this->element = element;
        this->link = link;
    }

    //method to update the element
    void updateData(int element){
        this->element = element;
    }

    //method to update or setup link
    void updateLink(node* link){
        this->link = link;
    }

    //method to get the element from the node
    int getElement(){
        return this->element;
    }

    //method to get the next node
    node* getNextNode(){
        return this->link;
    }
};

class Linkedlist{
protected:
    node* head;
public:

    //constructor for the Linked List class
    Linkedlist(){
        head = NULL;
    }

    //method returns true if the list is empty
    bool isEmpty(){
        return head == NULL;
    }

    //returns head node
    node* getHead(){
        return this->head;
    }

    //method to add a node at starting
    void addToStart(int element){
        node* tempNode = new node(element);
        if(head == NULL){
            head = tempNode;
        }
        else{
            tempNode->updateLink(head);
            head = tempNode;
        }
    }

    // method to add a node at the end
    void addToEnd(int element){
        node* tempNode = new node(element);
        node* p = head;
        if(head == NULL){
            head = tempNode;
            return;
        }
        else{
            while(p->getNextNode()!= NULL){
                p = p->getNextNode();
            }
            p->updateLink(tempNode);
            return;
        }
    }

    //method to display all the elements of the Linked List
    void display(){
        cout<<"\n";
        node* tempNode = head;
        while(tempNode != NULL){
            if(tempNode->getNextNode() != NULL)
                cout<<tempNode->getElement()<<" --> ";
            else
                cout<<tempNode->getElement();

            tempNode = tempNode->getNextNode();
        }
        return;
    }

    //method that returns the length of the Linked List
    int length(){
        int count = 0;
        if(this->isEmpty()){
            return -1;
        }
        node* tempNode = head;
        while(tempNode != NULL){
            count += 1;
            tempNode = tempNode->getNextNode();
        }
        return count;
    }

    //method to delete a data element
    void deleteData(int element){
        if(isEmpty()){
            cout<<"The List is Empty";
            return;
        }
        else{
            node* tempNode = head;
            node* prevNode = head;
            while(tempNode->getElement() != element){
                prevNode = tempNode;
                tempNode = tempNode->getNextNode();
            }
            prevNode->updateLink(tempNode->getNextNode());
            return;
        }
    }

};

int main() {
    Linkedlist l1;
    l1.addToStart(25);
    l1.addToStart(25);
    l1.addToStart(25);
    l1.addToStart(26);
    l1.addToStart(27);
    l1.addToStart(28);
    l1.display();

    l1.addToEnd(24);
    l1.addToEnd(23);
    cout<<"\n";
    l1.display();

    l1.deleteData(26);
    l1.display();
    return 0;
}