下面程序中A是抽象类。请在下面程序的横线处填上适当内容,以使程序完整,并使程序的输出为:
B1 called
B2 called
#include
using namespace std;
class A
{
public:
①
;
};
class B1:public A
{
public:
void display( ){coutdisplay( );
}
void main( )
{
B1 b1;
B2 b2;
A * p[2]={&b1,&b2};
for(int i=0;idisplay这句可知//该形参变量名为 p