Thread: calculate average from a file

What is your current code? Also, what is the sample input?

my current code:
I will fix the identing later.

Code:

#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
int num_females = 0;
int num_males = 0; 
int sum_males; 
int sum_females;

char name[25];
char gender;
char code[5];
int score;
int count = 0;

char reply;
ifstream infile;
string myfile;

//char process[200];

ifstream inputFile;

cout << "Enter file name with the extension(Example: scores.txt): " << endl;

cin >> myfile;

inputFile.open (myfile.c_str(), ios::in);

if(!inputFile)
 {
  cerr << "Can't open input file " << myfile << endl;
  cin >> reply;
  exit(1);
}



while(inputFile)
{
inputFile >> name;
cout << name;
inputFile >> gender;
if(gender == 'F')
{
	num_females++;
}
else
{
	num_males++;
}
cout << setw(5) << gender;
inputFile >> code;
cout << setw(3) << code;
inputFile >> score;
cout << setw(4) << score << endl;

//inputFile.getline(process,200);

}


 cout << "number of males = " << num_males;
 

 cin >> reply;
  return 0;
}

output:

Code:

Enter file name with the extension(Example: scores.txt):
scores.txt
Bailey    M CC  68
Harrison    F CC  71
Grant    M UN  75
Peterson    F UN  69
Hsu    M UN  79
Bowles    M CC  75
Anderson    F UN  64
Nguyen    F CC  68
Sharp    F CC  75
Jones    M UN  75
McMillan    F UN  80
Gabriel    F UN  62
    F     62
number of males = 5

that last F 62 is part of Gabriel and should not be there..
here is a copy of scores.txt

Code:

Bailey           M CC 68
Harrison         F CC 71
Grant            M UN 75
Peterson         F UN 69
Hsu              M UN 79
Bowles           M CC 75
Anderson         F UN 64
Nguyen           F CC 68
Sharp            F CC 75
Jones            M UN 75
McMillan         F UN 80
Gabriel          F UN 62

Originally Posted by mrsirpoopsalot

I will fix the identing later.

You could indent while you code. If you want such a lazy approach to indentation, use a source code formatting tool (your text editor/IDE may even come with one, and it probably can also be configured to help you indent while you code).

Originally Posted by mrsirpoopsalot

that last F 62 is part of Gabriel and should not be there..
here is a copy of scores.txt

I am unable to duplicate your output. However, I do get an output with this line repeated:

Code:

Gabriel    F UN  62

The reason is as before: you need to control the loop with the return value of the functions used to read. In this case you could write:

Code:

while (inputFile >> name >> gender)
{
    cout << name;
    if (gender == 'F')
    {
        num_females++;
    }
    else
    {
        num_males++;
    }
    cout << setw(5) << gender;
    inputFile >> code;
    cout << setw(3) << code;
    inputFile >> score;
    cout << setw(4) << score << endl;
}

Originally Posted by mrsirpoopsalot

well if i do something like this

Compare your code and mine. The critical difference is that you read into name twice on each iteration.

Originally Posted by mrsirpoopsalot

thank you it works, but im a little confused by what the condition is.

The underlying problem is that the EOF condition is only set when an attempt is made to read, and finds that it has reached the end of the file. This is why your original loop runs one extra time: the condition is tested and found that the EOF bit is not set, but actually the file has been completely read.

Originally Posted by mrsirpoopsalot

why cant we just use name and why name and gender?

To avoid the problem that you faced originally, it is enough to just read into name in the loop condition. The advantage of including gender, and even including code and score, is that the loop will terminate if there is invalid input, or if the last line is incomplete.

thank you