having junk when reading characters from text file

[chrisamgad]

Trying to read some characters from a text file into a 2d array but when I print my array, there are some junk characters...
Here is a screenshot of my text file http://prntscr.com/jg8v1f
and the output http://prntscr.com/jg8vl8
Thank you!

#include <iostream>
#include <string>
#include <fstream>
using namespace std;

void main()
{
	char A[8][8];
	char b;
	ifstream source;
	if (source.fail())
	{
		cout << "error!!" << endl;
		exit(1);
	}
	source.open("Easy.txt");
	for (int r = 0; r < 8; r++)
		for (int c = 0; c < 8; c++)
		{
			source.get(b);
			if (b == '#')
				A[r][c] = b;
			else
				if (b == '.')
					A[r][c] = b;
				else
					if (b == 'a')
						A[r][c] = b;
		}
	
	for (int r = 0; r < 8; r++)
	{
		for (int c = 0; c < 8; c++)
			cout << A[r][c];
		cout << endl;
	}
	source.close();
	system("pause");
}

[tpb]

It's more portable for main to return an int instead of being void.

You are checking for source.fail() before you even try to open the file!

When reading the file character-by-character, you are not taking into account the newline characters. I would just skip whitespace generally. The easiest way to do that is to use source >> b; instead of source.get(b).

BTW, it's generally better to use spaces instead of tabs since people's tab settings may be different from yours. The standard "tab" size these days is 4 spaces (definitely not 8!).

#include <iostream>
#include <string>
#include <fstream>
using namespace std;

int main() {
    char A[8][8];
    char b;

    ifstream source("Easy.txt");
    if (!source) {
        cerr << "error!!\n";
        exit(1);
    }

    for (int r = 0; r < 8; r++)
        for (int c = 0; c < 8; c++) {
            source >> b;
            switch (b) {
            case '#':
            case '.':
            case 'a':
                A[r][c] = b;
                break;
            default:
                cerr << "bad character in file: " << b << '\n';
                exit(1);
            }
        }

    for (int r = 0; r < 8; r++) {
        for (int c = 0; c < 8; c++)
            cout << A[r][c];
        cout << '\n';
    }
    
    // ifstreams automatically close when they go out of scope
    // (that's the magic of a destructor!)
}

[Handy Andy]

Hello chrisamgad,

Sometimes it is not the program that is the problem, but the input file containing characters that you do not see.

I found a program called HxD - Hexeditor found at https://mh-nexus.de/en/programs.php

It is helpful to see the hex numbers of what is exactly in a file. I have found some strange things in a text file that should not have been there.

If it is not the program check the "txt" file.

Hope that helps,

Andy

[chrisamgad]

It's more portable for main to return an int instead of being void.

You are checking for source.fail() before you even try to open the file!

When reading the file character-by-character, you are not taking into account the newline characters. I would just skip whitespace generally. The easiest way to do that is to use source >> b; instead of source.get(b).

BTW, it's generally better to use spaces instead of tabs since people's tab settings may be different from yours. The standard "tab" size these days is 4 spaces (definitely not 8!).

Great this worked for this specific code but what if I exchanged the 'a' character with a ' ' character (space) how could I make it work?

[tpb]

what if I exchanged the 'a' character with a ' ' character (space) how could I make it work

Then don't skip spaces. But you still need to deal with the newline char:

    for (int r = 0; r < 8; r++)
        for (int c = 0; c < 8; c++) {
            source.get(b);
            switch (b) {
            case '#':
            case '.':
            case ' ':
                A[r][c] = b;
                break;
            case '\n':
                break;   // ignore newlines
            default:
                cerr << "bad character in file: " << b << '\n';
                exit(1);
            }
        }

Reading line-by-line, it could be:

    string line;
    for (int r = 0; r < 8; r++) {
        getline(source, line);
        for (int c = 0; c < 8; c++)
            A[r][c] = line[c];   // assuming chars are good
    }

[chrisamgad]

string line;
    for (int r = 0; r < 8; r++) {
        getline(source, line);
        for (int c = 0; c < 8; c++)
            A[r][c] = line[c];   // assuming chars are good
    }

Thank you it worked!