填空题
下列程序的执行结果是______。
#include＜iostream.h＞
class Student
{
public:
Student(int xx){x=xx;}
virtual float calcTuition( );
protected:
int x;
};
float Studertt::calcTuition( )
{
return float(x*x);
}
class GraduateStudent:public Student
{
public:
GraduateStudent(int xx):Student(xx){}
float calcTuition( );
};
float Graduatestudent::calcTuition( )
{
return float(x*2);
}
void main( )
{
Student s(20);
GraduateStudent gs(30);
cout＜＜s.calcTuition( )＜＜" "＜＜gs.calcTuition( )＜＜endl;
//计算学生s和研究生gs的学费
}
【参考答案】
400 60