C++ program to overload Binary - minus operator for complex numbers using friend function.

#include<iostream.h>
#include<conio.h>
class complex{
float r,i;
public:
complex(){
r=0;
i=0;
}
complex(float real,float image){
r=real;
i=image;
}
void display(){
cout<<"complex Number is="<<r<<"+("<<i<<")i"<<endl;
}
friend complex operator-(complex c1,complex c2);
};
complex operator-(complex c1,complex c2){
complex temp;
temp.r=c1.r-c2.r;
temp.i=c1.i-c2.i;
return temp;
}
void main(){
complex c1(3,4),c2(2,-5),c3;
clrscr();
c1.display();
c2.display();
getch();
c3=c1-c2;
c3.display();
getch();
}