以下程序运行结果为1
#include<iostream.h>
class Sample
{
int n;
public:
Sample(int i){n=i;}
friend int add(Sample &s1,Sample &s2);
};
int add(Sample &s1,Sample &s2)
{
return s1.n+s2.n;
}
void main( )
{
Sample s1(10),s2(20);
cout<<add(s1,s2)<<endl;
}