Help identify the error pls.

ChaosCummings (3)
Hello, I was creating a project for my class at Devry. After pouring over the code for 3 days and trying to tweak a few things, I still wasn't able to identify the error. When I run the code it executes until after you press 'q'. Once that happens I get a write error. I asked my instructor to peruse the code as well and he was unable to identify the error either. Please assist.

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// William_wk5_iLab.cpp : main project file.

#include "stdafx.h"
#include "iostream"
#include "string"
#include "iomanip"

using namespace std;

int InputData(string playerName[], double score[], int &index, int &scoreCount, int ARRAYSIZE);
void DisplayPlayerData(string playerName[], double score[], int &index, int scoreCount, double avgScore);
double CalculateAverageScore(double score[], int &index, int scoreCount);
void DisplayBelowAverage(string playerName[], double score[], int &index, int scoreCount, double avgScore);

int main(array<System::String ^> ^args)
{
         const int ARRAYSIZE = 100;
	int scoreCount, index = 0;
	string playerName[ARRAYSIZE];
	double score[ARRAYSIZE], avgScore;

	cout << fixed << setprecision(2);

	while (1)
	{
		InputData(playerName, score, index, scoreCount, ARRAYSIZE);
		if (playerName[index] == "q" || playerName[index] == "Q")
			break;
	}

	avgScore = CalculateAverageScore(score, index, scoreCount);
	
	DisplayPlayerData(playerName, score, index, scoreCount, avgScore);

	DisplayBelowAverage(playerName, score, index, scoreCount, avgScore);

	system("pause");
         return 0;
}

int InputData(string playerName[], double score[], int &index, int &scoreCount, int ARRAYSIZE)
{
	while (index < ARRAYSIZE)
	{
		cout << "\n\nEnter Player Name (Q to quit): ";
		cin >> playerName[index];
		if (playerName[index] == "q" || playerName[index] == "Q")
			break;

		cout << "\nEnter score for " << playerName[index] << ": ";
		cin >> score[index];
		
		index++;
		scoreCount++;
	}
	return 0;
}

double CalculateAverageScore(double score[], int &index, int scoreCount)
{
	double avg = 0, total = 0;
	
	for (index = 0; index < scoreCount; index++)
	{
		total = total + score[index];
	}

	avg = total / scoreCount;
	return avg;
}

void DisplayPlayerData(string playerName[], double score[], int &index, int scoreCount, double avgScore)
{
	cout << "  Name             Score\n";
	
	for (index = 0; index < scoreCount; index++)
		cout << playerName[index] << setw(19) << score[index] << endl;

	cout << "\n\nAverage Score: " << avgScore << endl;
}

void DisplayBelowAverage(string playerName[], double score[], int &index, int scoreCount, double avgScore)
{
	cout << "\nPlayers who scored below average are:\n\n"
		<< "  Name             Score\n";
	
	for (index = 0; index < scoreCount; index++)
	{
		if (score[index] < avgScore)
			cout << playerName[index] << setw(19) << score[index] << endl;
	}
}
closed account (3qX21hU5)
I am not sure how you don't have any error when you main() is all messed up. It is illegal to declare it like int main(array<System::String ^> ^args) (As far as I know but I am pretty sure it is).


As for the error, the program is stopping in the CalculateAverageScore() function so narrow your search down to there.
ChaosCummings (3)
This generates the following error:

An unhandled exception of type 'System.AccessViolationException' occurred in wk5_ilab.exe

Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
SamuelAdams (1535)
no error, I think all I did was change line 15 and 37

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// William_wk5_iLab.cpp : main project file.

#include "stdafx.h"
#include "iostream"
#include "string"
#include "iomanip"

using namespace std;

int InputData(string playerName[], double score[], int &index, int &scoreCount, int ARRAYSIZE);
void DisplayPlayerData(string playerName[], double score[], int &index, int scoreCount, double avgScore);
double CalculateAverageScore(double score[], int &index, int scoreCount);
void DisplayBelowAverage(string playerName[], double score[], int &index, int scoreCount, double avgScore);

int main()
{
         const int ARRAYSIZE = 100;
	int scoreCount, index = 0;
	string playerName[ARRAYSIZE];
	double score[ARRAYSIZE], avgScore;

	cout << fixed << setprecision(2);

	while (1)
	{
		InputData(playerName, score, index, scoreCount, ARRAYSIZE);
		if (playerName[index] == "q" || playerName[index] == "Q")
			break;
	}

	avgScore = CalculateAverageScore(score, index, scoreCount);
	
	DisplayPlayerData(playerName, score, index, scoreCount, avgScore);

	DisplayBelowAverage(playerName, score, index, scoreCount, avgScore);

//system("pause");
         return 0;
}

int InputData(string playerName[], double score[], int &index, int &scoreCount, int ARRAYSIZE)
{
	while (index < ARRAYSIZE)
	{
		cout << "\n\nEnter Player Name (Q to quit): ";
		cin >> playerName[index];
		if (playerName[index] == "q" || playerName[index] == "Q")
			break;

		cout << "\nEnter score for " << playerName[index] << ": ";
		cin >> score[index];
		
		index++;
		scoreCount++;
	}
	return 0;
}

double CalculateAverageScore(double score[], int &index, int scoreCount)
{
	double avg = 0, total = 0;
	
	for (index = 0; index < scoreCount; index++)
	{
		total = total + score[index];
	}

	avg = total / scoreCount;
	return avg;
}

void DisplayPlayerData(string playerName[], double score[], int &index, int scoreCount, double avgScore)
{
	cout << "  Name             Score\n";
	
	for (index = 0; index < scoreCount; index++)
		cout << playerName[index] << setw(19) << score[index] << endl;

	cout << "\n\nAverage Score: " << avgScore << endl;
}

void DisplayBelowAverage(string playerName[], double score[], int &index, int scoreCount, double avgScore)
{
	cout << "\nPlayers who scored below average are:\n\n"
		<< "  Name             Score\n";
	
	for (index = 0; index < scoreCount; index++)
	{
		if (score[index] < avgScore)
			cout << playerName[index] << setw(19) << score[index] << endl;
	}
}
Last edited on
vlad from moscow (6539)
The problem in the original code is that after calling function InputData variable index becomes equal to ARRAYSIZE. After that you are trying to access playerName[ARRAYSIZE]

if (playerName[index] == "q" || playerName[index] == "Q")

However acceptable indexes for the array are 0 : ARRAYSIZE - 1
ChaosCummings (3)
Thank you SamuelAdams. It was indeed the parameters in the main function. Odd that it was that making the error. That is the default value for visual studio 2010 and I have created several programs with it in the past however this is the first one with functions so maybe that is what is making the difference. When I originally learned C++ I always used void main() so I think I will go back to that. Thank you for your help.
Chervil (7320)
ChaosCummings wrote:
When I originally learned C++ I always used void main() so I think I will go back to that.


That would be a retrograde step. main() returns type int
It is specified in the standard for C++.
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