有如下程序:
#include ＜iostream＞
using namespace std;
class Base
public:
void output() cout＜＜1;
virtual void Print() cout＜'B';
;
class Derived:public Base
public:
void output() cout＜2;
void Print() cout＜＜'D';
;
int main()
Base *ptr=new Derived;
ptr-＞output();
ptr-＞Print();
delete ptr;
return();

程序的输出结果是

A．1B
B．1D
C．2B
D．2D