C++: Errors while compilation of C++ program

Question

I am making a class Fraction with global functions usage My code looks like below:

#include<iostream>
using namespace std;

ostream & operator<<(ostream & os, Fraction & fr)
{
    return os << fr.get_num() << '/' << fr.get_den();
}

class Fraction
{
private:
    int num, den;
public:
int get_num()
    {
        return num;
    }
    int get_den()
    {
        return den;
    }
};

Main function has call : `cout << f2 << endl;
But i am getting following build erros while compilation:
Error C2805 binary 'operator <<' has too few parameters
fr: undeclared identifier
left of get_num must be struct/union/class

Is that the only error you get? Nothing about `Fraction` being undeclared when you define the `operator<<` function? You do know that in C++ you must declare symbols before you use them? — Some programmer dude, Mar 06 '16 at 05:35
Possible duplicate http://stackoverflow.com/questions/23335209/error-overloaded-operator-must-be-a-binary-operator-has-3-parameters — The Roy, Mar 06 '16 at 06:18
@DROY: thanks .. will check stack overflow other threads before posting :) — ojas, Mar 06 '16 at 10:18

score 1 · Accepted Answer · answered Mar 06 '16 at 07:13

You should change the order of your code like this:

class Fraction
{
private:
    int num, den;
public:
int get_num()
    {
        return num;
    }
    int get_den()
    {
        return den;
    }
};

ostream & operator<<(ostream & os, Fraction & fr)
{
    return os << fr.get_num() << '/' << fr.get_den();
}

C++: Errors while compilation of C++ program

1 Answers1