虚函数示例一则

#include <stdio.h>

class parent
{
public:
    virtual void v()
    {
        printf("p_v\n");
    }

    void f()
    {
        printf("p_f\n");
    }
};

class son : public parent
{
public:
    virtual void v()
    {
        printf("s_v\n");
    }

    void f()
    {
        printf("s_f\n");
    }
};

int main()
{
    class son s;
    class parent *p1 = (class parent *) &s;
    class son *p2 = &s;

    p1->v(); // s_v
    p1->f(); // p_f
    p2->v(); // s_v
    p2->f(); // s_f

    return 0;
}