First try with ARRAYS

I'm in deep trouble again. Sorry to be such a pest... I'm trying to learn to use Arrays. I understand that it's supposed to be the easy
way to program. Thus far, I have:

Code:

#include <iostream>
#include <fstream>
#include <string>
#include <ios>
#include <stdio.h>
#include <stdlib.h>
using namespace std;



int main ()
{
    
    cout << "You have chosen to play Florida's Mega_Money Lotto," << endl << endl;
    cout << " Please wait while I read the file " << endl << endl;
    
    int x = 0;

    // initialize 44 vairables from 0 thru 43

    
    int freq [44];

    for( int u = 0; u < 44; u++)
    {
        freq [u] = 0;

    }

    
    
    //Opens Temp_Program for reading the file
          
    ifstream a_file ( "D:\\LotteryPrograms\\Fla_Mega_Money\\Hist_temp.txt" );   

    for( int u = 0; u != EOF; u++)
    {
    
    a_file >> x;  // reads a number from the file MegaMil
    
    freq [ x - 1 ]++;

    }


    
    
    ofstream b_file ( "D:\\LotteryPrograms\\Fla_Mega_Money\\Loto_Temp_Program.txt" ); //Creates an instance of ofstream, and

    for( int u = 0; u < 44; u++)
    {
    
    b_file << "The number " << u + 1 << " appears " << freq [ u ] << " Times. " << endl << endl;

    }


    cout << "You should have it." << endl << endl;
    cin.get();


    return 0;

}

And when I build, there are no errors... but when I try to run the program, It just displays the first "cout" messages, and then
it just sits there (seemingly) doing nothing. The program does not crash. When I stop debugging I get the following errors.
What is a "PDB" file?

Code:

'Frequencies.exe': Loaded 'C:\Users\Therry.arkashea1-PC\Documents\Visual Studio 2010\Projects\Frequencies\Debug\Frequencies.exe', Symbols loaded.
'Frequencies.exe': Loaded 'C:\Windows\SysWOW64\ntdll.dll', Cannot find or open the PDB file
'Frequencies.exe': Loaded 'C:\Windows\SysWOW64\kernel32.dll', Cannot find or open the PDB file
'Frequencies.exe': Loaded 'C:\Windows\SysWOW64\KernelBase.dll', Cannot find or open the PDB file
'Frequencies.exe': Loaded 'C:\Program Files\AVAST Software\Avast\snxhk.dll', Cannot find or open the PDB file
'Frequencies.exe': Loaded 'C:\Windows\SysWOW64\msvcp100d.dll', Symbols loaded.
'Frequencies.exe': Loaded 'C:\Windows\SysWOW64\msvcr100d.dll', Symbols loaded.
The program '[6604] Frequencies.exe: Native' has exited with code 0 (0x0).

Can someone shed a little light on my problem, so I can understand what is happening? ... Thanks ... Therry

The problem is in your loops

Code:

    for( int u = 0; u != EOF; u++)
    {
        a_file >> x;  // reads a number from the file MegaMil
     
        freq [ x - 1 ]++;
   }

EOF is a value returned by C library functions that read files to indicate they have reached end of file. Its value is (often) negative. Incrementing a value starting at zero will keep producing positive values. That will continue until u has the maximum value an integer can represent (about 2147483647 for a 32 bit signed int). Incrementing a signed integral type past its maximum value then gives undefined behaviour (anything is allowed to happen, potentially including reformatting your hard drive).

The line "a_file >> x" will not magically set u to be EOF when the end of a_file is reached, so your loop will be executed virtually forever (until a crash occurs). So your code never actually checks if the end of file has been read, and will keep reading forever (until an integer overflow occurs, at which point all bets are off).

You need to read up a bit more on how to detect end of file and other error conditions in streams. Your code is looping without ever testing such conditions.

Unrelated to your qustion, your code is merrily incrementing freq[x] where x is the value input. That will also give undefined behaviour (writing over memory outside the array freq) if x is negative or x exceeds 43

Thanks guys. I solved the problem with:

Code:

 for( int u = 0; a_file; u++)

> What is a "PDB" file?
PDB Files

> 'Frequencies.exe': Loaded 'C:\Users\Therry.arkashea1-PC\Documents\Visual Studio 2010\Projects\Frequencies\Debug\Frequencies.exe', Symbols loaded.
This means you can debug your program at the source code level.

> 'Frequencies.exe': Loaded 'C:\Windows\SysWOW64\ntdll.dll', Cannot find or open the PDB file
This means you cannot debug ntdll.dll (at the source code level).
Not that you're likely to want to at the moment.

Code:

while ( a_file >> x )

Would be the way to loop reading the file.