Question

Error accessing structure member inside using member function of class. Hello i am unable to figure out the runtime error i am getting.
Actually i am trying t declare a struct inside a class then using the main method i m creating a pointer object of the class then using that object i trying to access the member function which tries to initialize the struct variables . but it i not happening

class UserInformation
{
public:
    struct UserInfo
    {
        int repu, quesCount, ansCount;
    };


public:
    void getInfo(int userId)
    {
        infoStruct.repu = userId;   //here is the error but i cant figure out why
        next->repu=userId;
    }

    void display()
    {
        cout<<"display";
    }

    UserInfo infoStruct,*next;
    int date;
};

int main()
{

    UserInformation *obj;
    obj->display();
    obj->getInfo(23);
    return 0;

}

Answer 1

This:

UserInformation *obj;

is an uninitialised pointer. Attempting to call member functions on it will lead to undefined behaviour.

You could do this:

UserInformation *obj = new UserInformation();
...
delete obj;  // Remember to clean up!

But in general, you should avoid using raw pointers and dynamically-allocated memory (i.e. from new).