Thread: Need help on Reading from a file

Originally Posted by abachler

last i checked fread is included with all C/C++ compilers. If it wasnt cin/cout would break since most compilers implement those using fread and other functions. C is a subset of C++, ergo anything that is C is also C++. perhaps you mean that fread isnt MFC, which isnt really c++ either, so i submit for everyone consideration that if its written in C/C++ then it IS C/C++.

Yes, of course, they are still valid - but someone who is on a course to learn C++ isn't supposed to use "classic" C functions to solve the problem - at least not if you want to get a good "score" for your excercises - and that's probably what the original poster would like in this case - I would personally mark someone on a C++ class as "failed" if they come up with a pure C solution - the fact that it works [or maybe not] would be secondary to showing an understanding of the language.

If on the other hand, this was about solving the problem "in any form that works", the aforementioned solution is fine. But we have to look at what the poster is asking for, not just find "any solution".

--
Mats

--

Then there has to be something that breaks your code, either the input file or compiler optimization, because it works fine for me both on debug and release with the input file you mentioned in the beginning of the thread.
EDIT: Why don't you try the following code and reply with what output you get:

Code:

int main()
{
    string name, majorname, coursename;
    ifstream inData;
    ofstream outData;
    double gpa = 0, mgpa = 0, fgpa = 0, averagef = 0, averagem = 0;
    int mcounter = 0, fcounter = 0;
    char gender = 0, show_gender = '\0';
    //char genderFromFile = 0;
    //char m = 0;
        
	inData.open("C:\\input.txt");
    //outData.open("outData.txt");
    
    cout << "Hello there, What is your name?" << endl;
    getline(cin, name);
    cout << "Welcome " << name << ".\n";
    cout << "Please enter your degree your majoring in." << endl;
    getline(cin, majorname);
    cout << "What the name of the course your taking for your major " << majorname << " ?\n";
    getline(cin, coursename);
    cout << "What is your gender? Enter m for male or f for female." << endl;
    cin >> show_gender;

    //outData << "Person's name is " << name << ". And there degree major is " << majorname << ". The class course name for there degree major is " << coursename << ".\n";

	while(inData >> gender >> gpa) 
	{
		cout << "DEBUG INFO: gender = " << gender << ", gpa = " << gpa << endl;
		if (gender == 'm')
		{
		   mcounter++; 
		   mgpa += gpa; 
		}
		else if (gender == 'f') 
		{
		   fcounter++; 
		   fgpa += gpa; 
		} 
	}

	if (show_gender == 'm')
	{
		averagem = mgpa / mcounter; // Average GPA
		cout << "The average for the male gpa is: " << averagem << endl;
	}
	else if (show_gender == 'f')
	{
		averagef = fgpa / fcounter; // Average GPA. Divide the total GPA by the number of entries found in the file.
		cout << "the average for the female gpa is: " << averagef << endl;
	} 

    _getch();
    return 0;
}

I added debug info to see if your program screws up somewhere, so post the outpost from the console window.

So, when you put in the input file, does it work?
EDIT: It might also be a good idea to check if the file is open after trying to open it. That way you check for errors, if the opening failed for some reason:

Code:

	inData.open("C:\\input.txt");
    outData.open("outData.txt");
	if ( !inData.is_open() )
	{
		cout << "ERROR: Could not open input file for reading!\n";
		return 1;
	}
	if ( !outData.is_open() )
	{
		cout << "ERROR: Could not open output file for writing!\n";
		return 1;
	}