Virtual Function

class A
{
public:
    virtual void f1()
    {
        cout << "Class A fun1" << endl;
    }
    void f2()
    {
        cout << "Class A fun2" << endl;
    }
};

class B : public A
{
public:
    void f1()
    {
        cout << "Class B fun1 " << endl;
    }
    void f2(int x)
    {
        cout << "Class B " << x << endl;
    }
};

void solve()
{
    A *ptr, obj1;
    B obj2;

    ptr = &obj2;
    ptr->f1();
}