pointer revision.cpp

#include<iostream>

using namespace std;

class complex{
    int a, b;
    public:
        void setnumber(int n1, int n2){
            a = n1;
            b = n2;
        }
        // below line means that non member funtions is allowed to access the private members using friend funtion 
        friend complex sumcomplex(complex o1, complex o2);
        void printnumber(){
            cout<<"your number is "<<a<<" + "<<b<<"i"<<endl;
        }
};

complex sumcomplex(complex o1, complex o2){
    complex o3;
    o3.setnumber((o1.a + o2.a), (o1.b + o2.b));
    return o3;
}

int main(){
    cout<<"this is tutorial 26"<<endl;
    complex c1, c2, sum;
    c1.setnumber(1, 4);
    c2.setnumber(5, 8);

    c1.printnumber();
    c2.printnumber();

    sum = sumcomplex(c1,c2);
    sum.printnumber();
    return 0;
}

/*
Properties of friend function
1. not in scope of class
2. since it is not in the scope of the class, it cannot be called from the object of that 
   class. like c1.sumcomplex--> Invalid
3. can be invoked without the help of any object
4. usually contains objects as arguments 
5. can be declared inside public or private section of the class
6. it cannot be access the members directly by their names and need objects_name.member_name
   to access any member
*/