how to pass pointer to constructor in c++

Question

i have a derived class that needs to take a pointer as a constructor for the base class.

how do you do this in c++, i tried it but it gave me a bug.
https://code.sololearn.com/cr3r6Rv2teYp/#cpp

Answer 1

#include <iostream>

using namespace std;

class Base{

public:
int *num;

Base(int *num);
virtual void print(){}; //print defination, virtual function must be defined, in base class.
};

Base::Base(int *num){
this->num = num;
}

class Derived : public Base {
public:
Derived(int *num) : Base(num){}; //passing pointer
void print();
};

void Derived::print(){
cout << "int value : " << *(this->num);
};

int main(){

int num = 5;
int *p = &num;

Derived derived(p);
derived.print();

return 0;
}