//showcases how you can use NULL.
#include <iostream>
using namespace std;

int main( ) {
    int x = 12345;
    int *ptrx = &x;

    while (ptrx) {
        cout << "Pointer ptrx points to " << ptrx << endl;
        ptrx = NULL;
    }

    cout << "Pointer ptrx points to nothing!" <<endl;
}