How to read from a text file and store to array list in c#?

Question

I'm trying to read a text file and store it's data to an array list. It's working without any errors. Inside of my text file is like this.

but in console output I can see this much of data.

Also Bolded numbers are not in my text file. Here is my code. how to solve this?? can Someone help me.. please...

        OpenFileDialog txtopen = new OpenFileDialog();
        if (txtopen.ShowDialog() == DialogResult.OK)
        {
            string FileName = txtopen.FileName;
            string line;
            System.IO.StreamReader file = new System.IO.StreamReader(FileName.ToString());
            while ((line = file.ReadLine()) != null)
            {
                list.Add(double.Parse(line));
            }
            //To print the arraylist
            foreach (double s in list)
            {
                Console.WriteLine(s);
            }
        }

Your variable FileName is already a string so you don't need to call ToString(). Also local variables should start with a lowercase letter. — Vincent, Aug 21 '15 at 08:01
@shona92 Your code is correct but your text file format is doubtful. You need to set every in new line as you shown in your input. — NASSER, Aug 21 '15 at 09:23
Side note: put `System.IO.StreamReader` into *using*, i.e. `using(System.IO.StreamReader file = new System.IO.StreamReader(FileName.ToString())) {...}` — Dmitry Bychenko, Aug 21 '15 at 09:43
@X-TECH text file format is .txt also every number is starting from new line. — shona92, Aug 21 '15 at 09:47

score 2 · Accepted Answer · answered Aug 21 '15 at 07:58

I think your list already contains some of the data, you should clear it before adding new file data to it.

OpenFileDialog txtopen = new OpenFileDialog();
if (txtopen.ShowDialog() == DialogResult.OK)
{
    list.Clear();   // <-- clear here

    string FileName = txtopen.FileName;
    string line;
    System.IO.StreamReader file = new System.IO.StreamReader(FileName.ToString());
    while ((line = file.ReadLine()) != null)
    {
        list.Add(double.Parse(line));
    }
    //To print the arraylist
    foreach (double s in list)
    {
        Console.WriteLine(s);
    }
}

Other wise every thing seems to be fine here.

Problem Solved. It worked. Thank you Very much for your kind support. — shona92, Aug 21 '15 at 09:52

Dmitry Bychenko · Answer 2 · 2015-08-21T09:42:01.070

Try using Linq which doesn't add anything to existing list:

if (txtopen.ShowDialog() == DialogResult.OK) {
  var result = File
    .ReadLines(txtopen.FileName)
    .Select(item => Double.Parse(item, CultureInfo.InvariantCulture));

  // if you need List<Double> from read values:
  //   List<Double> data = result.ToList();
  // To append existing list:
  //   list.AddRange(result);

  Console.Write(String.Join(Environment.NewLine, result));
}

How to read from a text file and store to array list in c#?

2 Answers2