单项选择题下面程序的运行结果为( )。# include <iostream.h>class A{public:A( ) {cout << 1 ;}~A( ) {cout << 2 ;}};class B:public A{public:B( ) {cout << 3 ;} ~B ( ) {cout << 4 ;}};void main ( ){B b;}
单项选择题下面程序的运行结果是( )。#include<iostream.h>class base{protected:int a;public:base( ){cout<< 0 ;}};class basel:virtual base{public:basel( ){cout<< 1 ;}};class base2:virtual base{public:base2( ){cout<< 2 ;}};class derived:public basel,public base2{public:derived( ){cout<< 3 ;}};void main( ){derived obj;cout<<endl;}