#include<iostream>
using namespace std;
class A
{public:
A(){a=5;}
void printa(){cout<<“A:a=”<<a<<endl;}
private:
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;
obj1.printa();
obj2.display1(obj1);
obj2.display2(obj1);
obj1.printa();
} 谁知道答案和详细点的解题步骤啊,帮帮忙,在线等
尤其是第三个数为什么是4不是5啊