Removing all whitespace from a list C#

Question

I'm reading all the lines from a text file into a list called 'masterToken', i'm trying to remove all the whitespace that will be in the list (all the spaces that were in the text file). masterToken = masterToken.Where(s => !string.IsNullOrWhiteSpace(s)).ToList(); is what i'm trying to use currently, it isn't working.

What is wrong with masterToken = masterToken.Where(s => !string.IsNullOrWhiteSpace(s)).ToList(); and/or is there a better way of achieving what I want?

Thanks

public static void Lex()
{        
  List<string> masterToken = File.ReadAllLines("C:\\Users\\Theo\\Documents\\Visual Studio 2017\\Projects\\Interpreter\\test.txt").ToList();

  foreach (var item in masterToken)
  {
    Console.Write(item.ToString());
  }

  masterToken = masterToken.Where(s => !string.IsNullOrWhiteSpace(s)).ToList();

  Console.WriteLine("");

  foreach (var item in masterToken)
  {
    Console.Write(item.ToString());
  }

  Console.ReadLine();
}

It will **only get rid of empty lines** as you are iterating over each line. You are not very clear in your question if you want to actually remove every white space everywhere so that words would justruntogetherlikethis. — Igor, Apr 04 '17 at 19:31
not sure why it isnt working. I did a test using the same linq statement and it gave me a new list with no whitespace entries. Unless you want it to eliminate any white space from any entries, and not just the entries that have only whitespace. — Kyle Rone, Apr 04 '17 at 19:32
Possible duplicate of [Efficient way to remove ALL whitespace from String?](http://stackoverflow.com/questions/6219454/efficient-way-to-remove-all-whitespace-from-string) — Massimiliano Kraus, Apr 04 '17 at 19:33
The code you have removes all blank lines from the file. Your question is unclear. Are you trying to remove all whitespace characters completely? — Rufus L, Apr 04 '17 at 19:33

Sergey Berezovskiy · Answer 1 · 2017-04-04T19:41:10.600

I suggest you use Regex.Replace to replace each sequence of whitespaces \s+ with empty string. Use this method to produce new strings and save results to list:

masterToken = masterToken.Select(t => Regex.Replace(t, @"\s+", "")).ToList();

Note that if you want to remove only leading and trailing whitespaces, then it's better to use Trim():

masterToken = masterToken.Select(t => t.Trim()).ToList();

And keep in mind that neither Trim nor Replace will not modify original string - all these methods return new string instances.

score 5 · Answer 2 · answered Apr 04 '17 at 19:32

5

Replace this line:

masterToken = masterToken.Where(s => !string.IsNullOrWhiteSpace(s)).ToList();

By this:

masterToken.ForEach(s => s = s.Replace(" ",""));

answered Apr 04 '17 at 19:32

Abdullah Dibas

1,499
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Nope, list will stay unchanged – Sergey Berezovskiy Apr 04 '17 at 19:33
also, `.Trim()` – BurnsBA Apr 04 '17 at 19:35

score 1 · Answer 3 · answered Apr 04 '17 at 19:34

1

Try regex

Regex.Replace(item,@"\s+","");

answered Apr 04 '17 at 19:34

Raj

4,405
13
59
74

Removing all whitespace from a list C#

3 Answers3