Redefinition of class in CPP File Error - c++

Question

I know there are plenty of questions like these, but I couldn't find a solution that worked for me.
Okay, I am trying to make simple fraction calculator than can add or subtract any number of functions and write the answer as a reduced fraction.
Example: input=
3/2 + 4/
8
, output =
2
I am trying overload operators in order to accomplish this.
So in the program, I am trying to develop the input consists of an expression made of fractions separated by the operators '+'or '-'.
The number of fractions in the expression is arbitrary.
Each of the following 6 lines is an example of valid input expression:
1/2 + 3/4
1/2 -5/7+3/5
355/113
3 /9-21/ -7
4/7-5/-8
-2/-3+7/5
The problem that I am having is that in when I run my Main CPP program it has a class redefinition error:
fraction.cpp:6:7: error: redefinition of 'Fraction'
class Fraction
^
./Fraction.h:7:7: note: previous definition is here
class Fraction{
However, that should not be a problem because I declared the class and member functions in my header files and defined them in my CPP file.
My following code is below:
Header File
#ifndef FRACTION_H
#define FRACTION_H
#include <iostream>
using namespace std;
class Fraction{
public:
Fraction(int , int );
int fraction(int,int);
void reduce_fraction(int *, int *);
Fraction& operator+(const Fraction& n);
Fraction& operator-(const Fraction& n);
friend ostream& operator<<(ostream &os, const Fraction& n);
friend istream& operator>>(istream &is, const Fraction& n);
};
#endif
CPP File
#include <iostream>
using namespace std;
#include "Fraction.h"
#include <stdexcept>
class Fraction
{
public:
Fraction::Fraction(int a, int b);
int find_gcd(int n1, int n2);
void reduce_fraction(int *nump, int *denomp)
{
int gcd;
gcd = find_gcd(*nump, *denomp);
*nump = *nump / gcd;
*denomp = *denomp / gcd;
if ((*denomp<0 && *nump < 0 ))
{
*denomp*=-1;
*nump*=-1;
}
else if (*denomp < 0 && *nump >0){
*denomp*=-1;
}
if ( *denomp ==0) {
throw invalid_argument( "Error: zero denominator" );
}
}
Fraction& Fraction::operator+(const Fraction& n) {
int denom = *denomp * n.denom;
int numera = (*nump * n.numera) + (n.denom * n.nump);
return Fraction(numera,denom);
}
Fraction& Fraction::operator-(const Fraction& n) {
int denom = *denomp * n.denom;
int numera = (*nump * n.numera) - (n.denom* n.nump);
return Fraction(numera, denom);
}
friend ostream& operator<<(ostream &os, Fraction& n)
{
if (n.numera == 0)
{
cout << 0 << endl;
return os;
}
else if (n.numera == n.denom)
{
cout << 1 << endl;
return os
}
else
{
cout << n.numera << '/' << n.denom << endl;
return os;
}
}
friend istream& operator>>(istream &os, Fraction& n)
{
char slash = 0;
return is >> n.numera >> slash >> n.denom;
}
};
#include <iostream>
using namespace std;
#include "Fraction.h"
#include <stdexcept>
class Fraction
{
public:
Fraction::Fraction(int a, int b);
int find_gcd(int n1, int n2);
void reduce_fraction(int *nump, int *denomp)
{
int gcd;
gcd = find_gcd(*nump, *denomp);
*nump = *nump / gcd;
*denomp = *denomp / gcd;
if ((*denomp<0 && *nump < 0 ))
{
*denomp*=-1;
*nump*=-1;
}
else if (*denomp < 0 && *nump >0){
*denomp*=-1;
}
if ( *denomp ==0) {
throw invalid_argument( "Error: zero denominator" );
}
}
Fraction& Fraction::operator+(const Fraction& n) {
int denom = *denomp * n.denom;
int numera = (*nump * n.numera) + (n.denom * n.nump);
return Fraction(numera,denom);
}
Fraction& Fraction::operator-(const Fraction& n) {
int denom = *denomp * n.denom;
int numera = (*nump * n.numera) - (n.denom* n.nump);
return Fraction(numera, denom);
}
friend ostream& operator<<(ostream &os, Fraction& n)
{
if (n.numera == 0)
{
cout << 0 << endl;
return os;
}
else if (n.numera == n.denom)
{
cout << 1 << endl;
return os
}
else
{
cout << n.numera << '/' << n.denom << endl;
return os;
}
}
friend istream& operator>>(istream &os, Fraction& n)
{
char slash = 0;
return is >> n.numera >> slash >> n.denom;
}
};
MAIN CPP FILE
#include "Fraction.h"
#include <iostream>
using namespace std;
int main()
{
Fraction x(2,3);
Fraction y(6,-2);
cout << x << endl;
cout << y << endl;
cin >> y;
cout << y << endl;
Fraction z = x + y;
cout << x << " + " << y << " = " << z << endl;
}
I am essentially having trouble with understanding why I am getting the previous definition error and how exactly to fix it. Also, if you see anything else wrong with my implementation in this program I would appreciate you telling me!
Thank you very much!

Answer 1

The way to define member functions in Fraction.cpp is not like this:
class Fraction
{
public:
void reduce_fraction(int *nump, int *denomp)
{
...
}
}
but rather like this:
void Fraction::reduce_fraction(int *nump, int *denomp)
{
...
}
More generally, you should not write this much code before testing any of it.