将运算符+和-重载为complex类的友元函数。

你不给分，。。很少人回答的，，，
#include

using namespace std;
class complexx
{
public:

complexx (double r = 0.0,double i = 0.0)
{
real = r;
imag = i;
}
friend complexx operator + (complexx c1,complexx c2);
friend complexx operator - (complexx c1,complexx c2);
void display();
private:
double real;
double imag;
};
complexx operator + (complexx c1,complexx c2)
{
complexx c3 ;
c3.real = c1.real + c2.real;
c3.imag = c1.imag + c2.imag;
return c3;
}
complexx operator - (complexx c1,complexx c2)
{
complexx c3 ;
c3.real = c1.real - c2.real;
c3.imag = c1.imag - c2.imag;
return c3;
}

void complexx ::display()
{
cout << "该复数为="<< real<<"+"< return ;
}
int main()
{
complexx a(5.0,6.0),b(2.1,4.2);
complexx ans1 = a+b;
complexx ans2 = a-b;
ans1.display();
ans2.display();
return 0;
}