#include
using namespace std;
class A
{
public:
A(){a=5;}
void printa(){cout<<"A:a="<<a<<endl;}
public:
int a;
friend class B;
};
class B
{
public:
void display1(A t)
{
t.a++;cout<<"display1:a="<<t.a<<endl;
}
void display2(A t)
{
t.a--;cout<<"display2:a="<<t.a<<endl;
}
};
int main()
{
A obj1;
B obj2;
cout<<obj1.a<<endl;
obj1.printa();
obj2.display1(obj1);
cout<<obj1.a<<endl;
obj2.display2(obj1);
obj1.printa();
return 0;
}
输出结果:
5
A:a=5
display1:a=6
5
display2:a=4
A:a=5