Why am I getting 2,3,4,0 as output i just need 2,3,4 please check my code guys i need help

Question

#include <iostream>
using namespace std;

class Node{
public:
int data;
Node *next;
};

void insertAtFirst(Node **head_ref, int data){
Node * new_node = new Node();
new_node->data = data;
new_node->next = (*head_ref);
(*head_ref) = new_node;
}

void printList(Node *trav){
while(trav!=NULL){
cout<<trav->data<<" ";
trav = trav->next;
}
}

int main(){
Node *head = new Node();
insertAtFirst(&head, 4);
insertAtFirst(&head, 3);
insertAtFirst(&head, 2);
printList(head);
}

Answer 1

Martin Taylor thank you so much
I wrote Node *head = NULL;
And my problem is solved and thanks for your suggestion to