有关虚函数的问题，期待解决！

[shuilongyin_00]

#include <iostream>
#include <string>
using namespace std;
class Student
 {public:
	Student(int,string,float);
	void display();
  protected:
	int num;
	string name;
	float score;
  };
Student::Student(int n,string nam,float s)
	{num=n;
	this->name=nam;
	score=s;
	}
void Student::display()
	{cout<<endl<<"num:"<<num<<endl;
	cout<<"name:"<<name<<endl;
	cout<<"score:"<<score<<endl;
	}
class Graduate:public Student
  {public:
	Graduate(int,string,float,float);
	virtual void display(); //虚函数
  private:
	float pay;
  };
void Graduate::display()
	{cout<<endl<<"num:"<<num<<endl;
	cout<<"name:"<<name<<endl;
	cout<<"score:"<<score<<endl;
	cout<<"pay="<<pay<<endl;
	}
Graduate::Graduate(int n,string nam,float s,float p):Student(n,nam,s),pay(p){}

int main()
	{Student stud1(101,"Li",87.5);  //定义Student类对象stud1
	Graduate grad1(2001,"Wang",98.5,563.5);  //定义Graduate类对象grad1
	Student *pt=&stud1;  //定义指向Student类对象的指针并指向stud1
	pt->display();  //调用stud1.display()函数
	//用指向基类对象的指针指向派生类对象
	pt=&grad1;  //指针指向grad1
	pt->display();  //调用grad1.display()函数
	return 0;
	}

初学C++，菜鸟请教！VC 6.0运行后为什么没有输出虚函数下的“pay”？

[clhposs]

将基类的这个函数设置为虚函数

那么所以继承该类的的子类如果重写该函数都会自动设置为virtual

[taodm]

认真看书，看看人家例题怎么实现虚函数的。

[setsailgo]

class Student
{public:
Student(int,string,float);
virtual void display(); //这个也应是虚的
protected:
int num;
string name;
float score;
};

[zdeepblue]

因为student的display()不是虚函数
把它改为

virtual void display();

[shuilongyin_00]

谢谢各位了！
解决了！