help variable changeing back after function

[diablo2713]

i need help with this code
exaple is input to the fuction (verc) is epspak 3.00.17
while it is isnside the fuction it converts correctly (coppak 8.00.03)
but when after the function is over i end up with epspak 8.00.03 or epspak 3.00.17 again :(
if i dont use a function for the conversion and have it straight on the main function it works fine.

please help

#include <cstdlib>
#include <iostream>
#include <string>
#include <sstream>
#include <windows.h>
#include <tchar.h>

using namespace std;
    string version;
    string app;
    string filen;
    string openr;
    int numbe;
    string don;
    int don2;


void xferf (string app, string verson)
{
std::string b; 
cout << "how many files?: ";
cin >> numbe;
while (numbe > 0)
{
cout << "what is the compressed file name?: ";
cin >> filen;
b = std::string("\\\\TPAJACOBL2W7\\archive\\xfer.bat ") + app + std::string(" ") + version + std::string(" ") + filen;
system( b.c_str() );
--numbe;
}
}

void verc (string app, string version)
{
       if (version == "3.00.03")              //start version conversion//
          {
            app = "coppak";
            version = "8.00.00";
          }
       if (version == "3.00.09")
          {
            app = "coppak";
            version = "8.00.01";
          }
       if (version == "3.00.14")
          {
            app = "coppak";
            version = "8.00.02";
          }
       if (version == "3.00.17")
          {
            app = "coppak";
            version = "8.00.03";
            cout << app << version << endl;
          }
        if (version == "3.00.16")
          {
            app = "cvxpak";
            version = "8.00.11";
          }
        if (version == "1.66.16")
          {
            app = "cvxpak";
            version = "6.00.15";
          }
        if (version == "3.05.01")
          {
            app = "cvxpak";
            version = "7.00.02";
          }
        if (version == "3.05.02")
          {
            app = "cvxpak";
            version = "7.00.03";
          }
        if (version == "3.05.03")
          {
            app = "cvxpak";
            version = "7.00.04";
          }
        if (version == "3.05.04")
          {
            app = "cvxpak";
            version = "7.00.05";
          }
        if (version == "3.07.02")
          {
            app = "hpspak";
            version = "4.03.01";
          }
        if (version == "3.07.03")
          {
            app = "hpspak";
            version = "4.03.02";
          }
        if (version == "3.07.04")
          {
            app = "hpspak";
            version = "4.03.03";
          }
          cout << app << version << endl;
}


void clean ()
{
std::string c;
c = std::string("\\\\TPAJACOBL2W7\\archive\\clean.bat ");
system( c.c_str() );
system("cls");
}

int done ()
{
  cout << endl;
  cout << "done with the dialin? (y/n): ";
  cin >> don;
  if (don == "y")
    {
        clean();
        return 0;
    }
  if (don == "n")
    {
        return 1;
    }

}




int main(int argc, char *argv[])
{
SetConsoleTitle(_T("Tools by Jacob") );

//star();

while (true)
{
don2 = 1;
cout << "welcome to file xfer assistant" << endl;
cout << "please note this is case sensitve use lowercase" << endl;
cout << endl;
std::string s;
cout << "what software version is it?: ";
cin >> app >> version;
if (app == "epspak");
{
        verc (app, version);
        cout << app << " " << version << endl;
        system ("pause");
}
cout << "open the relsapp? (y/n): ";
cin >> openr;
if (openr == "y")
{
s = std::string("\\\\TPAJACOBL2W7\\archive\\relsapp.bat ") + app + std::string(" ") + version;
system( s.c_str() );
}
if ( app == "buypak")
{
     s = std::string("\\\\TPAJACOBL2W7\\archive\\shochk.bat ") + app + std::string(" ") + version;
system( s.c_str() );
}
if ( app == "citpak")
{
          s = std::string("\\\\TPAJACOBL2W7\\archive\\shochk.bat ") + app + std::string(" ") + version;
system( s.c_str() );
}
if ( app == "coppak")
{
          s = std::string("\\\\TPAJACOBL2W7\\archive\\shochk.bat ") + app + std::string(" ") + version;
system( s.c_str() );
}
if ( app == "cvxpak")
{
          s = std::string("\\\\TPAJACOBL2W7\\archive\\shochk.bat ") + app + std::string(" ") + version;
system( s.c_str() );
}
if ( app == "hpspak")
{
          s = std::string("\\\\TPAJACOBL2W7\\archive\\shochk.bat ") + app + std::string(" ") + version;
system( s.c_str() );
}
if ( app == "shopak")
{
          s = std::string("\\\\TPAJACOBL2W7\\archive\\shochk.bat ") + app + std::string(" ") + version;
system( s.c_str() );
}
if ( app == "epspak")
{
          s = std::string("\\\\TPAJACOBL2W7\\archive\\shochk.bat ") + app + std::string(" ") + version;
system( s.c_str() );
}
        cout << app << " " << version << endl;
        system ("pause");
        xferf(app, version);
        don2 = done();
}




    system("PAUSE");
    return EXIT_SUCCESS;
}                                                   // end of main function 

[Zhuge]

Pass by reference if you want the changes inside the function to be reflected outside of it.

[diablo2713]

thanks a bunch that worked
although i had to look up passing by reference cause im a noob lol
for any other noobs to pass by reference put an "&" symbol between your variable type and the variable name in the function declaration

example of that is
void verc (string app, string version) //non pass by refrance

void verc (string & app, string & version) // pass by refrance

[Austin J]

Be careful not to overuse it though. There's an option between the two for a reason.