#include<iostream.h>
class A
{  int a,b;
  public:
    friend void setval(int i,int j);
    void showA()
    {cout<<a<<","<<b<<endl; }                                                                                                         
};                  
void setval(int i,int j)
{a=i; b=j;}
void main()
{A obj1;
 setval(2,3);
 obj1.showA();
}
这是一道改错题，我知道友元函数里德a，b不是A下的a，b，但我不知道怎么改，求各位大虾指点迷津！

#include<iostream.h>
class A
{  int a,b;
  public:
    friend void setval(A&,int i,int j);
    void showA()
    {cout<<a<<","<<b<<endl; }                                                                                                         
};                  
void setval(A& a,int i,int j)
{a.a=i; a.b=j;}
void main()
{A obj1;
setval(obj1,2,3);
obj1.showA();
}