友元的练习

#include<iostream>
#include<string>
using namespace std;
class build
{
friend void goodgay1(build *build);
friend void goodgay(build &build);
public:
string keting;
private:
string woshi;
public:
build()
{
this->keting="客厅";
this->woshi="卧室";
}
};
void goodgay1(build *a)
{
cout<<"好基友1正在访问"<<a->keting<<endl;
cout<<"好基友1正在访问"<<a->woshi<<endl;
}
void goodgay(build &build)
{
cout<<"好基友正在访问"<<build.keting<<endl;
cout<<"好基友1正在访问"<<build.woshi<<endl;
}
void test()
{
build build;
goodgay(build);
}
int main()
{
test();
build *a=NULL;
goodgay1(a);
}