下面程序的结果是 ______。 #include<iostream.h> class A public: virtual void fun()=0; ; class B:public A public: void fun () cout<< new file ; ; class C: public A public: void fun ()cout<< open file << ; class D: public A public: void fun () cout<< save file n ; ; void main() A a,*p; B b; C c; D d; p=&c; p->fun (); p=&b; p->fun (); p=&d; p->fun();
A.new file open file save file
B.new file new file new file
C.编译出错
D.open file new file save file