Virtual Function in OOPS

* /program to illustrate virtual function./ *
#include < iostream > using namespace std;
class base
{
    public: void display()
    {
        cout << "\ndisplay base";
    }
    virtual void show()
    {
        cout << "\nshow derived";
    }
};
class derived: public base
{
    public: void display()
    {
        cout << "\nderived display";
    }
    void show()
    {
        cout << "\nshow derived";
    }
};
int main()
{
    base b;
    derived d;
    base * bptr;
    cout << "\nbptr points to base";
    bptr = & b;
    bptr - > display();
    bptr - > show();
    cout << "\nbptr points to derived";
    bptr = & d;
    bptr - > display();
    bptr - > show();
    return 0;
}