Create 2D array from txt file

Question

Okay so I've managed to read in a .txt file... now I'm trying to figure the best way to convert this information into a 2D array.

My text file (first two number provide height and width):

5
5
0,0,0,0,0
0,0,0,0,0
0,0,1,0,0
0,1,1,1,0
1,1,1,1,1

My C# / XNA:

string fileContents = string.Empty;
try
{
    using (StreamReader reader = new StreamReader("Content/map.txt"))
    {
        fileContents = reader.ReadToEnd().ToString();
    }
}
catch (Exception e)
{
    Console.WriteLine(e.Message);
}

Now what I need to do next is define the size of the 2-dimensional map array and then populate the entry values... this is where I'm getting a bit stuck and have found various ways I can loop through the data but I don't think any of them have been terribly tidy.

What I've tried to do is have one loops which splits by newline... and then another loop which splits by comma delimiter.

Is this the best way to do it... or are there better alternatives?

Answer 1

It can be done with LINQ but that is only practical when you want (accept) an array-of-array, int[][] instead of a straight 2-dimensional int[,] .

int[][] data = 
    File.ReadLines(fileName)
    .Skip(2)
    .Select(l => l.Split(',').Select(n => int.Parse(n)).ToArray())
    .ToArray();

Answer 2

The code below doesn't require the first to rows in your sample .CSV file:

5
5

I'd prefer it this way, but as a consequence, the code below reads the file twice. It would take a small modification use the first two rows in your sample instead.

private int[,] LoadData(string inputFilePath)
{
  int[,] data = null;

  if (File.Exists(inputFilePath))
  {
    Dictionary<string, int> counts = GetRowAndColumnCounts(inputFilePath);

    int rowCount = counts["row_count"];
    int columnCount = counts["column_count"];

    data = new int[rowCount, columnCount];

    using (StreamReader sr = File.OpenText(inputFilePath))
    {
      string s = "";
      string[] split = null;

      for (int i = 0; (s = sr.ReadLine()) != null; i++)
      {
        split = s.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);

        for (int j = 0; j < columnCount; j++)
        {
          data[i, j] = int.Parse(split[j]);
        }
      }
    }
  }
  else
  {
    throw new FileDoesNotExistException("Input file does not exist");
  }

  return data;
}

private Dictionary<string, int> GetRowAndColumnCounts(string inputFilePath)
{
  int rowCount = 0;
  int columnCount = 0;

  if (File.Exists(inputFilePath))
  {
    using (StreamReader sr = File.OpenText(inputFilePath))
    {
      string[] split = null;
      int lineCount = 0;

      for (string s = sr.ReadLine(); s != null; s = sr.ReadLine())
      {
        split = s.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);

        if (columnCount == 0)
        {
          columnCount = split.Length;
        }

        lineCount++;
      }

      rowCount = lineCount;
    }

    if (rowCount == 0 || columnCount == 0)
    {
      throw new FileEmptyException("No input data");
    }
  }
  else
  {
    throw new FileDoesNotExistException("Input file does not exist");
  }

  Dictionary<string, int> counts = new Dictionary<string, int>();

  counts.Add("row_count", rowCount);
  counts.Add("column_count", columnCount);

  return counts;
}

Answer 3

Here's the solution I've come up with which appears to work.

int[,] txtmap;
int height = 0;
int width = 0;
string fileContents = string.Empty;

try
{
    using (StreamReader reader = new StreamReader("Content/map.txt"))
    {
        fileContents = reader.ReadToEnd().ToString();
    }
}
catch (Exception e)
{
    Console.WriteLine(e.Message);
}

string[] parts = fileContents.Split(new string[] { "\r\n" }, StringSplitOptions.None);
for (int i = 0; i < parts.Length; i++)
{
    if (i == 0)
    {
        // set width
        width = Int16.Parse(parts[i]);
    }
    else if (i == 1)
    {
        // set height
        height = Int16.Parse(parts[i]);

        txtmap = new int[width, height];
    }

    if (i > 1)
    {
        // loop through tiles and assign them as needed
        string[] tiles = parts[i].Split(new string[] { "," }, StringSplitOptions.None);
        for (int j = 0; j < tiles.Length; j++)
        {
            txtmap[i - 2, j] = Int16.Parse(tiles[j]);
        }
    }
}