A simple program showing inheritance

#include <iostream>
using namespace std;

class base {
  int i, j;
public:
  void set(int a, int b) { i = a; j = b; }
  void show() { cout << i << " " << j << "\n"; }
};

// inheritance
class derived : public base {
  int k;
public:
  derived(int x) { k = x; }
  void showk() { cout << k << "\n"; }
};

int main()
{
  derived ob(3);

  ob.set(1, 2); // access member of base
  ob.show();    // access member of base

  ob.showk();   // uses member of derived class

  return 0;
}