填空题
下列程序的执行结果是 【12】 。
#include＜iostream. h＞
class Student
{
public:
Student(int xx){x=xx;}
virtual float calcFuition( );
protected:
int x;
}
float Student:: 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()＝＝end1;
//计算学生s和研究生gs的学费
}
【参考答案】
400 60