填空题

以下程序的执行结果是______。 #include<iostream.h> class base { public: virtual void who(){cout<<"base class"<<endl:} }; class derrvel:public base { public: void who(){cout<<"derivel class"<<endl:} }; class derive2;public base { public: void who() {cout<<"derive2 class"<<endl;} }; void main() { base obj1,*P; derive1 obj2; derive2 obj3: p=&obj1; p->who(); p=&obj2: p->who(); p=&obj3; p->who(); }

【参考答案】

base class derivel class derive2 class