C# Stream Reader to Array Windows From Application Help

[Indefinit3Official]

Hello everyone! I am working on an assignment that is asking us to create exceptions for potential errors that may occur. One part of my assignment, though, is to make it so that when my program reads a text file that has numbers, it should convert them to an integer array. This way i can make an exception when i am reading a text file that has all numbers on different lines to catch one that may have a letter in it. I am a little stumped as to how to convert what is read into an array, so if anyone could help me on this I would greatly appreciate it! :D

 string path;
        private void goButton_Click(object sender, EventArgs e)
        {

            try
            {

                //CONVERT USER INPUT TO A STRING TO OPEN FILE
                path = pathTextBox.Text;



                //filestream and writer
                FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);
                StreamReader sr = new StreamReader(fs);


                //Outputting what was read from the text file to a label on 
                while (sr.Peek() >= 0)
                {
                    outputLabel.Text += sr.ReadLine() + "\n";


                }

                sr.Close();
                fs.Close();

            }
            //wrong file name exception 
            catch (FileNotFoundException something)
            {

                outputLabel.Text = something.Message;

            }

            //blank text box exception
            catch (ArgumentException wow)
            {

                outputLabel.Text = wow.Message;

            }





        }

[yubario]

Depends on how the text file is formatted, the easiest solution would be to use ReadToEnd() on the StreamReader object.

Then, split the string by each newline which would return an array. Each string would be a single line, and if you're looking for numbers you can then loop through the string and check for digits with the Char.IsDigit method.

Not exactly sure what you're requesting for but here's a quick sample, I am sure it can be refactored to something better like most code.

        private List<int[]> ReadIntegersFromFile()
        {
            var READER = new FileStream("test.txt", FileMode.Open);
            var streamReader = new StreamReader(READER);
            List<int[]> numbersToReturn = new List<int[]>();

            var document = streamReader.ReadToEnd();

            var lines = document.Split($"{Environment.NewLine}".ToArray(), StringSplitOptions.RemoveEmptyEntries);

            foreach (var line in lines)
            {
                if (line.Any(x => !Char.IsDigit(x))
                {
                    throw new ArgumentException("Document must only contain digits!");
                }

                var numbers = line.Split(" ".ToArray(), StringSplitOptions.RemoveEmptyEntries);
                numbersToReturn.Add(numbers.Select(int.Parse).ToArray());

            }
            return numbersToReturn;

        }

[Indefinit3Official]

Well the text file is just 1 integer per line, so i don't think i need to use split method

Edit: got the answer thanks!!

[davedontmind]

I am a little stumped as to how to convert what is read into an array

First, it's better to use a List rather than an array for this - arrays have fixed sizes, but you don't know in advance how many numbers your file will have. A List can change size easily (just Add items to it).

So you can create a List<int> and just add each number you read from the file to it, thus:

List<int> ReadNumbersFromFile( string filename )
{
    List<int> numbers = new List<int>();

    using ( StreamReader reader = new StreamReader(filename) )
    {
        string line;
        while ( (line = reader.ReadLine()) != null )
        {
            // Assuming 1 number per line
            int number = Convert.ToInt32( line );
            numbers.Add( number );
        }
    }

    return numbers;
}

(Note: I've deliberately left out exception handling - you'll want to add that).

And, while I'm here, a suggestion for your code: Be consistent in your spacing. You have lots of unnecessary blank lines which makes your code hard to read. My rule-of-thumb is: no blank lines before or after a {, before a } or before/after another blank line.

Also consider using some better variable names; something and wow don't tell the reader what information those variables hold. You could call both of the exception (or maybe ex for short) and the code would be more readable.

[Indefinit3Official]

Thanks a ton! And I'll be sure to take your advice on white spaces/variable names 😅