Thread: Help with this while loop

something is wrong with my while loop. it prints the last code twice. it takes 3 numbers from a text file and calculates the monthly payment and prints to screen. the problem is it prints the last monthly payment twice.

Code:

#include <iostream>
#include <cstdlib>
#include <fstream>
#include <cstdio>
#include <cmath>

using namespace std;

void usage()
{
  cout << "Usage: loancalc <filename>" << endl;
  exit (1);
}

double monthlyPayment (double amount, int months, double interest)
{
  double ratem, expm, mp;
  ratem = interest / 1200.00;
  expm = 1.0 + ratem;
  mp = (ratem * pow(expm, months) * amount) / ( pow(expm, months) -1.0); 
  return mp;
}

void displayLoanInfo (double amount, int months, double interest)
{
  double mp, total;
  printf ("%10.2f %8d %10.2f ",amount, months, interest);
  if (amount > 0 && months > 0 && interest > 0)
  {
    mp = monthlyPayment(amount, months, interest);
    total = mp * months;
    printf ("%11.2f %12.2f \n",mp, total);
  }
  else printf ("    <error>      <error>\n");
}

int main (int argc, char **argv)
{
  ifstream infile;
  double d1,d2;
  int i;
 
  if (argc !=2)
  {
    usage ();
  }

  infile.open (argv[1]);

  printf("                                   Monthly\n");
  printf("    Loan      Months      Rate     Payment      Total\n");
  printf("-----------------------------------------------------------\n");
  
  if (!infile.fail ())
  {
    while (!infile.eof ())
    {
      infile >> d1 >> i >> d2;
      displayLoanInfo (d1, i, d2);
    }
  }
  else cout << "No File!" << endl;
  
  infile.close ();
  return 0;
}

thanks for replying so quickly
but I kinda figured it was doing it because it was reading a blank line but I wasnt to sure if that was the reason. should I use another stoping condition in a while loop?