c++友元类

#include <iostream>
using namespace std;

class myComplex //复数类
{
private:
double real,imag;
public:
myComplex();
myComplex(double r,double i);
friend class oper;
};

myComplex::myComplex()
{
real=0;
imag=0;
}

myComplex::myComplex(double r,double i)
{
real=r;
imag=i;
}

class oper //操作类
{
public:
myComplex addCom(myComplex c1,myComplex c2); //c1,c2都是对象，即复数
void outCom(myComplex c);
};

myComplex oper::addCom(myComplex c1,myComplex c2)
{
return myComplex(c1.real+c2.real,c1.imag+c2.imag);
}

void oper::outCom(myComplex c)
{
cout<<"("<<c.real<<","<<c.imag<<")";
}

int main()
{
myComplex c1(1,2),c2(3,-4),result;
oper o;
result=o.addCom(c1,c2); //友元类的体现
o.outCom(c1);
cout<<"+";
o.outCom(c2);
cout<<"=";
o.outCom(result);
cout<<endl;
return 1;
}

结果：