版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/jlran/article/details/52700119
#include <iostream>
using namespace std;
//?若B类是A类的友员类，则B类的所有成员函数都是A类的友员函数
//?友员类通常设计为一种对数据操作或类之间传递消息的辅助类
class Test{
public:
Test(){
a = 10;
b = 20;
}
void getAB(){
cout << "a : " << a << " b: " << b << endl;
}
friend void setAB(Test *t1, int a, int b);
friend class te;
//te是test的友元类
private:
int a;
int b;
};
void setAB(Test *t1, int a, int b){
t1->a = a;
t1->b = b;
}
class te{
private:
Test t1;
public:
void setTest(int a, int b){
t1.a = a;
t1.b = b;
}
void getTestAB(){
t1.getAB();
}
};
int main()
{
Test t1;
t1.getAB();
//t1.a = 10;
setAB(&t1,20,30);
//通过友元函数 修改Test类的私有属性
t1.getAB();
cout << "友元类: " << endl;
te t;
t.getTestAB();
t.setTest(1,1);
t.getTestAB();
getchar();
return 0;
}