class A

{

public:

    A()

    {

        printf("A()\n");

    }

    virtual ~A()

    {

        printf("~A()\n");

    }

};

class B

{

public:

    B()

    {

        printf("B()\n");

    }

    ~B()

    {

        printf("~B()\n");

    }

};

class C:public A, public B //继承用“,”隔开每个类前面必须有public否则默认为private

{

public:

    C()

    {

        printf("C()\n");

    }

    ~C()

    {

        printf("~C()\n");

    }

};

int _tmain(int argc, _TCHAR* argv[])

{

    {

        C c; //可以正确构造和析构

    }

    {

        A *a = new C;

        delete a;//有virtual会一次调用C,A,B的析构函数，正确执行

    }

    {

        B *b = new C;

        delete b;//没有virtual会直接调用B的析构,不会调用A,C的析构函数错误

    }

    getchar();

    return ;

}