Question

I am getting segmentation fault in this code but i cant figure out why. I know a segmentation fault happens when a pointer is NULL, or when it points to a random memory address.

 q = p;
        while(q -> link != NULL){
            q = q -> link;
        }
        t = new data;
        t -> city = cityName;
        t -> latitude = lat;
        t -> longitude = lon;
        q -> link = t;

This is the error am actually getting in console:

line 33: 2219 Segmentation fault    sh "${SHFILE}"

Answer 1

In the else clause in Database::add, you do not set t->link = NULL, so it is uninitialized.

You should add a constructor for data that initializes its members, or use the value-initializing new to ensure that everything is initialized correctly:

t = new data(); // note the parentheses