自考新教材-p272_2

源程式：

#include <iostream>

using namespace std;

class Bas

{

public:

~Bas()

{

cout << "Bas析構函數" << endl;

}

virtual void f() = 0;

};

class Dev :public Bas

{

public:

~Dev()

{

cout << "Dev析構函數" << endl;

}

virtual void f()

{

cout << "Dev::f" << endl;

}

};

int main()

{

Bas *a;

Dev p;

a = &p;

a->f();

system("pause");

return 1;

}

運作結果：