function already has a body and redefinition of string variable - c++

Question

ERRORS:
error messages
mainFun.cpp:
#include <iostream>
#include <string>
#include "userCheckFunH.h"
using namespace std;
int yesNo;
string passName;
string userName;
string userRetrieve()
{
if (userName == "")
{
cin >> userName;
}
else
{
if (userName == "devin772" || userName == "guestacc")
{
yesNo = 1;
}
else
{
yesNo = 0;
}
}
return userName;
}
int userCheck()
{
return yesNo;
}
int main()
{
do
{
string userN;
system("cls");
// ui
cout << " DH DB " << endl;
cout << "x----------------x" << endl;
//username
cout << "username: " << endl;
cout << "> ";
// fun call
userRetrieve();
int continueP = userCheck();
cout << "" << endl;
// password
if (continueP = 1 && userRetrieve() == "devin772")
{
cout << "password:" << endl;
cout << "> ";
cin >> passName;
if (passName == "12qwaszx")
{
cout << "" << endl;
system("pause");
system("cls");
// run program
dataBaseRunP("admin");
npOpen();
cout << "" << endl;
system("pause");
return 0;
}
}
else if (continueP = 1 && userRetrieve() == "guestacc")
{
cout << "password:" << endl;
cout << "> ";
cin >> passName;
if (passName == "guestguest")
{
cout << "" << endl;
system("pause");
system("cls");
// run program
dataBaseRunP("regUser");
npOpen();
cout << "" << endl;
system("pause");
return 0;
}
}
else
{
cout << "Invalid username." << endl;
cout << "" << endl;
system("pause");
userRetrieve() = "";
userName = "";
yesNo = 0;
passName = "";
}
} while (true);
system("pause");
}
nextFun.cpp :
#include <iostream>
#include "userCheckFunH.h"
using namespace std;
string userLevel;
int dataBaseRunP(string authLevel)
{
string fileName;
if (authLevel == "regUser")
{
fileName = "user.txt";
userLevel = fileName;
}
else if (authLevel == "admin")
{
fileName = "admin.txt";
userLevel = fileName;
}
else
{
cout << "ERROR - user level not found." << endl;
system("pause");
exit(EXIT_FAILURE);
return 0;
}
exit(EXIT_SUCCESS);
return 0;
}
void npOpen()
{
string fileNpName;
fileNpName = userLevel;
fileNpName = "notepad \"" + fileNpName + "\"";
system(fileNpName.c_str());
}
userCheckFunH.h:
#ifndef USERCHECKFUN_H
#define USERCHECKFUN_H
#include "nextFun.cpp"
int dataBaseRunP();
void npOpen();
#endif
i'm attempting to make a basic program that allows you to open files hidden through windows in a basic c++ program. keep getting this error. tried different header guards, variable names, function names, file names. i also delete nextFun.cpp and the program ran fine. i can't get past this error, please help.
thanks! :)

Answer 1

It is highly unusual to include a cpp file, which you do in userCheckFunH.h, with
#include "nextFun.cpp"
Your nextFun.cpp file includes this very header:
#include "userCheckFunH.h"
Since you cpp file doesn't have an include guard (which is fine) you end up with the functions in the cpp file twice.
Don't include the cpp file in the header.