Thread: cannot access private member declared in class

hello all,
I am one of millions who is new to C++.. I am writing this program about rational numbers and stuck here, I just cant figure where is the prob.. I already searched almost every c++ tutorial but still I am just lost... When try to execute the prog I got errors like:
--------------------Configuration: MyRationalNumber - Win32 Debug--------------------
Compiling...
RationalNumbers.cpp
rationalnumbers.cpp(43) : error C2248: 'num' : cannot access private member declared in class 'RationalNumbers'
rationalnumbers.h(12) : see declaration of 'num'
rationalnumbers.cpp(43) : error C2248: 'den' : cannot access private member declared in class 'RationalNumbers'
rationalnumbers.h(13) : see declaration of 'den'
m_RationalNumbers.cpp
Error executing cl.exe.

MyRationalNumber.exe - 2 error(s), 0 warning(s)

Can you look at my code and tell me the prob?PLEASE...

// Class declaration

#ifndef RATIONALNUMBERS_H
#define RATIONALNUMBERS_H
#include<iostream>
using namespace std;


class RationalNumbers{

friend ostream& operator<<(ostream &os, const RationalNumbers &f);
private:
int num;
int den;

public:
RationalNumbers();
RationalNumbers(int n,int d);
RationalNumbers operator+(RationalNumbers f);
RationalNumbers operator-(RationalNumbers f);
int getLCD(int,int);

};

#endif //RATIONALNUMBERS_H

======================================
Here is my class definition
======================================
#include"RationalNumbers.h"
#include<iostream>
using namespace std;

RationalNumbers::RationalNumbers(){
num = 1;
den = 1;
}

RationalNumbers::RationalNumbers(int n,int d){
num = n;
//check if denominator is not zero
if(d)
den = d;
else{
cout << "Invalid denominator for "<< this << "... Setting denominator to 1." << endl;
den = 1;
}
}

RationalNumbers RationalNumbers:perator +(RationalNumbers f){
RationalNumbers F;
int lcd = F.getLCD(F.den,f.den);
F.num = lcd * num + lcd * f.num;
F.den = lcd;
return F;
}

int RationalNumbers::getLCD(int d1, int d2){
int temp, den1,den2;
den1 = d1;
den2 = d2;
//loop until value second denominator is becomes zero
while(d2){
temp = d2;
d2 = d1 % d2;
d1 = d2;
}
return (den1 * den2 / d1);
}

ostream &operator<<(ostream & os, const RationalNumbers &f){
os << f.num << "/" << f.den;
return os;
}

=================================================
main functions
=================================================
#include"RationalNumbers.h"
#include<iostream>
using namespace std;

int main(){
RationalNumbers A(1,2);
cout << A;
cout << endl;
return 0;
}

Just trying to display Rational Number A, I am not still done with the quarter of the code and I am already stuck..... 8(

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As to your problem, the code compiles fine for me. The error seems to indicate that the operator<< is not a friend, but it is in the posted code.

sorry for not following the forum's rules... Apologies....
Already included it in my notes...

Generally making operator<< and operator>> friends (as well as other non-member operators) is considered better than adding accessor functions just for them. The operators are still part of the interface, and its better encapsulation to make them friends than to expose the value to the world when you don't want to.

If you can already implement the operator through the existing interface without making it a friend or exposing more internal data, then that would probably be best.