以下是引用心动音符在2006-6-11 16:10:01的发言：
人们为什么说C++难！难在哪里啊？
#include <iostream>
using namespace std;
class Student
{public:
Student(int n,float s):num(n),score(s){}
void display() const;
void change(int n,float s) const;
private:
mutable int num;
mutable float score;
};
void Student::change(int n,float s) const
{num=n;score=s;}
void Student::display() const
{cout<<num<<" "<<score<<endl;}
int main()
{
const Student stud(101,78.5);
stud.display();
stud.change(101,80.5);
stud.display();
return 0;
}这题错哪了