Multiple errors after splitting main file into header, source and main

Question

I had this program working perfectly in one main file.

But I needed to separate it into header and source files.

I'm now getting a ton of errors and I am at a loss for what I am missing here.

Tested the main with a classmates header and source files and it worked. So the problem is in the header or source file.

#ifndef JMTDRational
#define JMTDRational
#include <string>
#include <sstream>

class JMTDRational{
    private:
        int numerator;
        int denominator;
    public:
        void set_numerator(int num);
        void set_denominator(int den);
        int get_numerator() const;
        int get_denominator() const;
        std::string r_to_string();
        double r_to_decimal();
        JMTDRational add(const JMTDRational & obj);
        JMTDRational subtract(const JMTDRational & obj);
        JMTDRational multiply(const JMTDRational & obj);
        JMTDRational divide(const JMTDRational & obj);
        JMTDRational();
        JMTDRational(int num,int den);
        JMTDRational reduce(const JMTDRational);
        int gcd(int n, int d);

};

#endif // JMTDRational

#include "JMTDRational.h"

    void JMTDRational::set_numerator(int num)
        {
            numerator = num;
        }

    void JMTDRational::set_denominator(int den)
        {
            if (den != 0) {
                denominator = den;
            }
            else{
                denominator = 1;
            }
        }

    int JMTDRational::get_numerator() const
        {
            return numerator;
        }

    int JMTDRational::get_denominator() const
        {
            return denominator;
        }

    string JMTDRational::r_to_string()
        {
            ostringstream str1, str2;
            str1 << get_numerator();
            str2 << get_denominator();
            string temp = str1.str() + "/" + str2.str();

            return temp;
        }

    double JMTDRational::r_to_decimal()
        {
            double temp = get_numerator() / get_denominator();
            return temp;
        }

    JMTDRational::JMTDRational(int num,int den) {
            numerator = num;
            denominator = den;

        }
    JMTDRational::JMTDRational() {
            numerator = 0;
            denominator = 1;
        }

    JMTDRational JMTDRational::reduce(const JMTDRational)
        {
            int temp_numerator = get_numerator() / gcd(get_numerator(),get_denominator());
            int temp_denominator = get_denominator() / gcd(get_numerator(),get_denominator());
            JMTDRational temp(temp_numerator,temp_denominator);
            return temp;
        }
    int JMTDRational::gcd(int n, int d)
        {
                if (d == 0)
                    return n;
                return gcd(d, n % d);
        }

    JMTDRational JMTDRational::add(const JMTDRational & obj)
        {
            int temp_numerator = get_numerator() * obj.get_denominator() + obj.get_numerator() * get_denominator();
            int temp_denominator = get_denominator() * obj.get_numerator();
            JMTDRational temp(temp_numerator,temp_denominator);
            return temp;
        }

    JMTDRational JMTDRational::subtract(const JMTDRational & obj)
        {
            int temp_numerator = get_numerator() * obj.get_denominator() - obj.get_numerator() * get_denominator();
            int temp_denominator = get_denominator() * obj.get_numerator();
            JMTDRational temp(temp_numerator,temp_denominator);
            return temp;
        }

    JMTDRational JMTDRational::multiply(const JMTDRational & obj)
        {
            int temp_numerator = get_numerator() * obj.get_numerator();
            int temp_denominator = get_denominator() * obj.get_denominator();
            JMTDRational temp(temp_numerator,temp_denominator);
            return temp;
        }

    JMTDRational JMTDRational::divide(const JMTDRational & obj)
        {
            int temp_numerator = get_numerator() * obj.get_denominator();
            int temp_denominator = get_denominator() * obj.get_numerator();
            JMTDRational temp(temp_numerator,temp_denominator);
            return temp;
        }

Answer 1

In the header file You have defined the name: JMTDRational to an empty value.

#ifndef JMTDRational
#define JMTDRational
#include <string>
#include <sstream>

class JMTDRational{

So everywhere in your code where You have the name JMTDRational the preprocessor replaces it with "nothing".

For example:

    JMTDRational add(const JMTDRational & obj);
    JMTDRational subtract(const JMTDRational & obj);

becomes:

    add(const& obj);
    subtract(const & obj);

which is invalid code.

You need a unique hardened name in the Header guard:

#define JMTDRATIONAL_H_HEADER