problem with Header and cpp files.

[Gonen]

Hello,

I wrote a class that called CRational.

I wrote its header , and its cpp files.

I want to use my CRational class in other cpp file(that file is located in the same folder where CRational.h and CRational.cpp are located)

So in the start of the file , I wrote this :

#include <iostream>
#include "CRational.h" 

but When I am compile my code , I got some errors like that

undefined reference to `CRational::setNumerator(int)
undefined reference to `CRational::setDenominator(int)
undefined reference to `CRational::operator+(CRational)

etc...
and when I am trying to include CRational.cpp , it says that I am doing redefinition of main....

anyone know what do?

thanks for the helpers. |

[mahlerfive]

Sounds like you might have put something which should have gone into the header file into the cpp file, or vice versa. Can you post CRational.h and CRational.cpp?

[Gonen]

this is CRational.h

#ifndef CRATIONAL_H_INCLUDED
#define CRATIONAL_H_INCLUDED
#pragma once

class CRational
{
    private:
    int denominator , numerator;
    public:
    CRational(int , int);
    CRational () {};
    void setDenominator(int);
    void setNumerator(int);
    int getDenominator();
    int getNumerator();
    CRational reciprocal();
    void recReciprocal();
    CRational operator +(CRational);
    CRational operator -(CRational);
    CRational operator *(CRational);
    CRational operator /(CRational);
    CRational reduce();
    double printDouble();
    void printAsFraction();
    void printOneLine();
};

#endif // CRATIONAL_H_INCLUDED 

and this is CRational.cpp

#include<iostream>
#include "CRational.h"

using namespace std;



CRational::CRational(int a , int b)
{
    denominator=a;
    numerator=b;
}

int CRational::getDenominator()
{
    return denominator;
}

int CRational::getNumerator()
{
    return numerator;
}

void CRational::setDenominator(int dem)
{
    denominator=dem;
}

void CRational::setNumerator(int nem)
{
    numerator=nem;
}

CRational CRational::reciprocal()
{
    int a;
    a=denominator;
    denominator=numerator;
    numerator=a;
    CRational r(denominator , numerator);
    return r;
}

CRational CRational::operator+ (CRational param)
{
    CRational temp;
    int nem = numerator*param.getNumerator();
    temp.setNumerator(nem);
    int dem1 = (nem/numerator) * denominator;
    int dem2 = nem/param.getNumerator() * param.getDenominator();
    temp.setDenominator(dem1+dem2);
    return temp;
}

CRational CRational::operator- (CRational param)
{
    CRational temp;
    int nem = numerator*param.getNumerator();
    temp.setNumerator(nem);
    int dem1 = (nem/numerator) * denominator;
    int dem2 = nem/param.getNumerator() * param.getDenominator();
    temp.setDenominator(dem1-dem2);
    return temp;
}

CRational CRational::operator* (CRational param)
{
    CRational temp;
    int nem = numerator*param.getNumerator();
    temp.setNumerator(nem);
    int dem = denominator*param.getDenominator();
    temp.setDenominator(dem);
    return temp;
}

CRational CRational::operator/ (CRational param)
{
    param=param.reciprocal();
    CRational temp;
    int nem = numerator*param.getNumerator();
    temp.setNumerator(nem);
    int dem = denominator*param.getDenominator();
    temp.setDenominator(dem);
    return temp;
}

CRational CRational::reduce()
{
    CRational temp;
    int little;
    if (denominator>=numerator)
    {
        little=denominator;
    }
    else
    {
        little=numerator;
    }
    int num=0;
    for (int i=1;i<=little;i++)
    {
        if (denominator%i==0 && numerator%i==0)
        {
            num=i;
        }
    }
    temp.setDenominator(denominator/num);
    temp.setNumerator(numerator/num);
    return temp;
}


double CRational::printDouble()
{
    double i = (double)denominator/(double)numerator;
    return i;
}

void CRational::printAsFraction()
{
    cout<<denominator<<endl<<"--"<<endl<<numerator<<endl;
}

void CRational::printOneLine()
{
    cout<<denominator<<"/"<<numerator;
}

int returnInt(char a[], int n , int n2)
{
    if (a[n2]=='\0')
    {
        return n;
    }
    n=n*10+a[n2]-'0';
    returnInt(a , n , n2+1);
    return n;
}

void recReciprocal(char a[] , char b[])
{
    if (a[0]=='.' || b[0]==-'.')
    {
        return;
    }
    else
    {
       int dem=returnInt(a , 0 , 0);
       int num=returnInt(b , 0 , 0);
       CRational r(dem , num);
       char c[256];
       char d[256];
       cout<<"enter a number"<<endl;
       cin>>c;
       cout<<"enter a number"<<endl;
       cin>>d;
       recReciprocal(c,d);
       cout<<r.reciprocal().printDouble()<<endl;
    }
}



int main()
{
    char a[256];
    char b[256];
    cout<<"enter a number"<<endl;
    cin>>a;
    cout<<"enter a number"<<endl;
    cin>>b;
    int a2=returnInt(a , 0 , 0);
    int b2=returnInt(b , 0 , 0);
    CRational r(a2 , b2);
    char c[256];
    char d[256];
    cout<<"enter a number"<<endl;
    cin>>c;
    cout<<"enter a number"<<endl;
    cin>>d;
    int c2=returnInt(c , 0 , 0);
    int d2=returnInt(d , 0 , 0);
    CRational r2(c2 , d2);
    (r*r2).reduce().printAsFraction();
    (r*r2).reduce().printOneLine();
    return 0;
}

[mahlerfive]

Not really sure why you are getting the errors you are, but I would move all functions that are not part of the CRational class to another file... for example, your main(), returnInt(), and returnReciprocal() should not be in CRational.cpp.

Also, all the #include's the class needs, and the using namespace commands can be put inside the header file right under the #ifndef/#define guards.

See if that fixes anything..

[exception]

Are you sure that CRational.cpp is compiled? And that then CRational.o is linked to main.o? (Or whatever your compiler calls these files). What compiler/IDE are you using?

[Gonen]

mahlerfive ,
It worked.
thanks a lot.

and thank you too exception.