Unused variable issue

[noahk81]

Hi, I am currently writing a program for converting zip codes to bar codes. When attempting to compile my program it says that my variable checkDigit is set but not used. However I do believe I am using it and do not know how to fix this problem. Any help is appreciated, thank you.

 #include <iostream>
#include <iomanip>
#include <cstdlib>
using namespace std;
string getDigitCode(char input);
int getCheckDigitValue(int sum);
string barcode(int sum);
int main(int argc, char const *argv[]) {
  int sum;
  int checkDigit;
  string barValue; 
  cout << "Enter zipcode:  " << endl;
  cin >> sum; 
  if(sum > 0)
  {             
    checkDigit = getCheckDigitValue(sum);
    barValue = barcode(sum);
    cout << "Your barcode is: ";
    cout << barValue << endl;
  }
  else
  {    
    cout << endl << "You have entered an invalid zip code." << endl;
  }
  return 0;
} /// main
string getDigitCode (char input){
  if (input == 0) return "||:::";
  else if (input == 1) return ":::||";
  else if (input == 2) return "::|:|";
  else if (input == 3) return "::||:";
  else if (input == 4) return ":|::|";
  else if (input == 5) return ":|:|:";
  else if (input == 6) return ":||::";
  else if (input == 7) return "|:::|";
  else if (input == 8) return "|::|:";
  else if (input == 9) return "|:|::";
  else return "Invalid postal code";
}
string barcode(int sum)
{
  int checkDigit = getCheckDigitValue(sum);
  int first;
  int second;
  int third;
  int fourth;
  int fifth;
  first = sum % 10;
  sum = sum / 10;
  second = sum % 10;
  sum = sum / 10;
  third = sum % 10;
  sum = sum / 10;
  fourth = sum % 10;
  sum = sum / 10;
  fifth = sum % 10;
  sum = sum / 10;
  string barcode = "|" + getDigitCode(fifth) + getDigitCode(fourth) + getDigitCode(third) + getDigitCode(second) + getDigitCode(first) + getDigitCode(checkDigit) + "|";
return (barcode);
}
int getCheckDigitValue (int sum)
{
  int sumDigits = 0;
  int checkDigit;
  while(sum)
  {
    sumDigits = sumDigits + sum % 10;
    sum = sum / 10;
  }
  checkDigit = 10 - (sumDigits % 10);
  return checkDigit;
}

[Ganado]

  if(sum > 0)
  {             
    checkDigit = getCheckDigitValue(sum);
    barValue = barcode(sum);
    cout << "Your barcode is: ";
    cout << barValue << endl;
  }

You assign the result of the getCheckDigitValue function to a variable called checkDigit in your main function, but don't use the variable in main to actually do anything.