c++友元函数学习

#include<iostream>
#include<string.h>
using namespace std;

class student
{
private:
    char name[10];
    int score;

public:
    char* gan(student &student1,student &student2);
    friend void disp(student &student1);//友元函数

    student(char tname[10]="",int tscore=0)//构造函数
    {
        strcmp(name,tname);
        score=tscore;
    }
};

void disp(student &student1)//友元函数定义是不需引用对象
    {
        if(student1.score>=80)
        cout<<student1.score<<endl;
    }

char* student::gan(student &student1,student &student2)
{
    if(student1.score>student2.score)
        return student1.name;
    return student2.name;
}

void main()
{
    student st1("hc",100);
    student st2("s2",99);
}