Need help troubleshooting

[Huppa]

What am I doing wrong that when my studentCounter & totalPassedCounter outputs, there's always one extra? Is that because I initalized number to = 1 to start? How could I go about fixing this?

//examgrade.cpp

#include <iostream.h>
#include <iomanip.h>
#include <conio.h>

           
   int main()
           
   
   {
   
      int number, studentCounter, totalPassedCounter, totalFailed;
   
      number=1;
      studentCounter = 0;
      totalPassedCounter = 0;
      totalFailed = 0;
   
   
      while (number==1)
      {
         studentCounter++;
         totalPassedCounter++;
         cout << "Enter result (1 = pass, 2 = fail, -1 = done): ";
         cin >> number;
         cout << endl;
      }
      while (number==2)
      {
         studentCounter++;
         totalFailed++;
         cout << "Enter result (1 = pass, 2 = fail, -1 = done): ";
         cin >> number;
         cout << endl;
      }
      if (number==-1)
      {
         cout << "There was a total of " << studentCounter << " students that took the test.\n";
         cout << "The number of students that passed was: \n" << totalPassedCounter;
         cout << "The number of students that failed was: \n" << totalFailed << endl << endl;
      }
      if (totalPassedCounter > 8){
         cout << "You should raise tuition." << endl;
      
      }
   
      return (0);
   
   }

[MikeyBoy]

Why are you incrementing studentCounter and totalPassedCounter before you've ever asked the user for the first result?

[wildblue]

Yes, you started out with 1 that didn't correspond to a student passing. I think I'd initialize the variable to 0 and restructure how the code loops.

For example, what are you expecting to happen if someone enters a 1 in this loop? i.e. they enter a passing grade after a failing grade? It's not going to jump back to the previous while.

while (number==2)
      {
         studentCounter++;
         totalFailed++;
         cout << "Enter result (1 = pass, 2 = fail, -1 = done): ";
         cin >> number;
         cout << endl;
      }

maybe something like this...

- ask for entry

While sentinel value not entered
- increment student counter
- if pass, increment pass counter
- if fail, increment fail counter
- ask for entry

[Huppa]

Why are you incrementing studentCounter and totalPassedCounter before you've ever asked the user for the first result?

Because I'm new to C, and trying to learn. It's the same reason I asked for help in the first place. Forgive me for being under the "Beginner" section of the site.

Yes, you started out with 1 that didn't correspond to a student passing. I think I'd initialize the variable to 0 and restructure how the code loops.

Thanks, I'll try what you recommended.

[MikeyBoy]

Because I'm new to C, and trying to learn. It's the same reason I asked for help in the first place. Forgive me for being under the "Beginner" section of the site.

Um, I meant that as a genuine question. For all I know, you had a particular reason for wanting to do it that way. There's no need to be defensive.

[Huppa]

Um, I meant that as a genuine question. For all I know, you had a particular reason for wanting to do it that way. There's no need to be defensive.

I apologize. It seemed as though it was a sarcastic question.