C++ Homework, What am I doing wrong?

[shadowhawk2020]

Here is the code I have come up with for this week, when I run it it reads the same record over and over, and never stops. I am sure I just did some stupid mistake, but I have been working on this so long today, my eyes are going to bleed.

//Jason Watson
//SPD_6_5

#include <fstream>
#include <iostream>
#include <cstdlib>
#include <iomanip>

using namespace std;

int main ()
{
    float TotalTax, TotalGrossEarnings, TotalMedicalLevy, TotalEarnings;   
    TotalTax = 0;     //Set TotalTax to 0
    TotalGrossEarnings = 0;  //Set TotalGrossEarnings to 0
    TotalMedicalLevy = 0;   //Set TotalMedicalLevy  to 0
    TotalEarnings = 0;    //Set TotalEarnings to 0
    short hours, rate, employeenumber; 
    cout <<"Employeee earnings and medical levy report: "<< endl << endl;          //Display Heading
    cout <<"Emp #"<<setw(11)<<"Gross"<<setw(14)<<"Tax"<<setw(16)<<"Levy"<<setw(13)<<"Net"<<endl<<endl;    //Read Employee Record
    ifstream empfile;                            
    empfile.open("empfile.txt",ios::in);         //Open File  
    if(empfile)                                 //Check For Error
    {
                empfile >> employeenumber >> hours >> rate;                                    
                do
                {
                        TotalGrossEarnings += hours*rate;                   //Calluclations
                        TotalTax += hours*rate*0.15;                                   
                        TotalMedicalLevy += hours*rate*0.01;
                        TotalEarnings += (hours*rate)-((hours*rate)*0.15)-((hours*rate)*0.01);
                        cout.setf(ios::fixed);
                        cout<<employeenumber<<setw(15)<<setprecision(2)<<hours*rate*1.00;
                        cout<<setw(15)<<hours*rate*0.15<<setw(15)<< hours*rate*0.01;
                        cout<<setw(15)<<(hours*rate)-((hours*rate)*0.15)-((hours*rate)*0.01)<<endl<<endl;
                        empfile >> employeenumber >> hours >> rate;                  
                }
                while (!empfile.eof());
                empfile.close();                                      //Close Employee file
                cout << endl;
                cout << "Total Groass Earnings: " << TotalGrossEarnings << endl;
                cout << "Total Tax: " << TotalTax << endl;
                cout << "Total Medical Levy: " << TotalMedicalLevy << endl;
                cout << "Total Earnings: " << TotalEarnings << endl << endl;
    }
    else {cout << "Error opening data file" << endl;} 

    cin.get();
    return 0;
}

Thank you for any help you can give

Shadow

[Nagisan]

Where are you increasing the file line? In my experience, when you read a file, you MUST tell it to go to the next line somehow......not too familiar with C++ but I would assume it works in a similar way. Currently, you are not telling it to read a line, just a file, so it is never reaching the end-of-file, because it is stuck reading the first line.

Here we go:

  if (myfile.is_open())
  {
    while (! myfile.eof() )
    {
      getline (myfile,line);
      cout << line << endl;
    }
    myfile.close();
  }

C++ may be different, as it doesn't appear to need to increase the line, but use a while loop instead of a do loop and it looks like it should work (just pulled this off the internet though).

[El Marto]

yeh your problem is definetly with detecting the end of file. i did something verrry similar a few weeks back. will try and find it and get back.

[Bassem]

I don't know much about C++ but does this have anything to do with the fact that you're closing the file stream inside the while loop?

[Chester0]

Try:

char c;
do
                {
                       //stuff;           
                }
                while (empfile >> noskipws >> c);

maybe the myfile.eof() returns true when it finds the '/n' char, if it only reads one line?

noskipws flag

edit

yep getline() might do the trick too.

I don't know much about C++ but does this have anything to do with the fact that you're closing the file stream inside the while loop?

He is not.

do
                {
                        TotalGrossEarnings += hours*rate;                   //Calluclations
                        TotalTax += hours*rate*0.15;                                   
                        TotalMedicalLevy += hours*rate*0.01;
                        TotalEarnings += (hours*rate)-((hours*rate)*0.15)-((hours*rate)*0.01);
                        cout.setf(ios::fixed);
                        cout<<employeenumber<<setw(15)<<setprecision(2)<<hours*rate*1.00;
                        cout<<setw(15)<<hours*rate*0.15<<setw(15)<< hours*rate*0.01;
                        cout<<setw(15)<<(hours*rate)-((hours*rate)*0.15)-((hours*rate)*0.01)<<endl<<endl;
                        empfile >> employeenumber >> hours >> rate;                  
                } //end do
                while (!empfile.eof());
                //out of do-while loop here
                empfile.close();  //safe

Edited March 10, 2010 by Chester0

[boogerjones]

The problem is you're using the stream operators to read consecutive values; the stream has no idea of the length of each value. So if you do the following:

int a = 23;
int b = 46;
int c = 0;
int d = 0;
fstream << a << b;
fstream >> c >> d;

You'll end up with c = 2346 and d = 0 since the stream doesn't know where to stop reading the integer. Furthermore, we have no idea what your "test.txt" file looks like. Upload it.

Use the ofstream.write and ifstream.read functions instead.

Or better yet, put all of the employee hours, rate, etc into a structure and read/write the structure from/to the file in one call. I think I already told you to do this in another thread; I'm telling you to do it again. It'll make this a lot easier.