Unhandled Exception: Access Violation

Warmaster (9)
Hello, and thank you to anyone willing to help.

I am a bit frustrated since I am trying to get my error handling working and I keep running into this unhandled exception error.

I am simply writing a function to check the input to make sure it is not out of the range of the the seating arrangement ie. if the user wants 3 rows (0 to 2) and 4 seats (a, b, c, d), then I want to make sure when they reserve a flight that the rows are not less than 0 or greater than 2 (or 1 less than input_row). Also, I will make sure that the user enters a letter for the seat assignment, and that the seat letter they choose is not less than a, or greater than input_seat.

I keep getting this unhandled exception error when I select a row that is greater than what is mapped, or less than 0...ie. if I select 2 rows for input row, then try to assign myself row 5 for a reservation, I end up with this error. What am I doing wrong? 

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//Airplane seat assignment

#include <iostream>
#include <cmath>
#include <string>

using namespace std;

typedef char* charArray;
typedef charArray* char2Array;

char again;

void check_row(int& input_row);
void check_seat(char& input_seat, int& col);
void display_seating(char2Array a, int rows, int seats);

//void assign_seat(char2Array a, int rows, int row, int col, char& valid);

int main()

{
using namespace std;

int row, col;
int input_row;
char valid = 'T';

char input_seat;
int rows, seats;

cout << "Please list the number of rows the plane has: ";
cin >> rows;

cout << "Seats in each row: ";
cin >> seats;

charArray *seat = new charArray[rows];
for(row = 0; row < rows; row++)
seat[row] = new char[seats];

for(row = 0; row < rows; row++)
for(col = 0; col < seats; col++)
seat[row][col] = static_cast<char>(toupper('A') + col);

do
{
cout << endl;
display_seating(seat,rows,seats);

cout << "\nPlease select a seating assignment from the seating arrangement displayed above."
	 << "Enter the numeric row number" 
	 << " followed by the letter of your seat choice: ";
cin >> input_row >> input_seat;
col = toupper(input_seat) - toupper('A'); 



	do
	{
		//check_row(input_row);
		if (seat[input_row][col] == 'X')
			{
				cout << "\nYou chose: "<< input_row << static_cast<char>(toupper('A') + col) << " which was reserved by another customer.";
				valid = 'F';
			}
		else
			{
				seat[input_row][col] = 'X';
				cout << "\nYou successfully reserved seat: " << input_row << static_cast<char>(toupper('A') + col) << " Thank you for flying with Argyle Express.";
				valid = 'T';
			}
	}while (valid = 0);

	


cout << "\nWould you like to make another reservation?";
cin >> again;

}while (again != 'N' || again != 'n');

return 0;
}

 
void display_seating(char2Array a, int rows, int seats)

{
using namespace std;
for(int row = 0; row < rows; row++)
{

cout << row;
for(int col = 0; col < seats; col++)

{

cout << a[row][col];

}

cout << endl;

}

}

void assign_seat(char2Array a, int rows, int row, int col, char& valid)
{
	using namespace std;

	// if the chosen seat has a x in it, then the seat is not valid
	if (a[row][col] == 'X')
		{
			valid = 'F';
		}
	else //The seat is valid and will become reserved by placing a x in it
		{
			a[row][col] = 'X';
			valid = 'T';
		}
}

void check_row(int& input_row)
{
	if (input_row < 0 || input_row > input_row -1 || input_row != isdigit(input_row))
		cout << "The row you selected is not available.";
	return;
}

void check_seat(char& input_seat, int& col)
{
	// This function checks to make sure the input is within the acceptable range for 'row' and 'col'
	using namespace std;

	if (!isalpha(input_seat))
		cout << "You must select a letter"; 
	if ((col < 'a' || col > input_seat) || (col < 'A' || col > input_seat ))
		cout << "You chose seat " << static_cast<char>(toupper('A') + col) << " but must choose a seat \n "
			 << "that is between A and " << static_cast<char>(toupper('A') + col);
}


Thank you,

Warmaster
Moschops (7244)
if (input_row < 0 || input_row > input_row -1 || input_row != isdigit(input_row))

This is your check. So if there are 5 rows in the aircraft, which of these checks is checking that input_row is one of those 5? None of them.

input_row > input_row -1

When will this ever be false?
Last edited on
Warmaster (9)
doh! I have been messing with this for 2 days now and I am apparently not seeing straight..thanks for pointing that out.
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