How do I remove all non alphanumeric word from a List<string>

Question

How do I remove all non alphanumeric words from a list of strings (List<string>) ?

I found this regex !word.match(/^[[:alpha:]]+$/) but in C# how can I obtain a new list that contains only the strings that are purely alphanumeric ?

Answer 1

You can use LINQ for this. Assuming you have a theList (or array or whatever) with your strings:

var theNewList = theList.Where(item => item.All(ch => char.IsLetterOrDigit(ch)));

Add a .ToList() or .ToArray() at the end if desired. This works because the String class implements IEnumerable<char>.

Answer 2

  Regex rgx = new Regex("^[a-zA-Z0-9]*$");
  List<string> list = new List<string>() { "aa", "a", "kzozd__" ,"4edz45","5546","4545asas"};
  List<string> list1 = new List<string>();
  foreach (var item in list)
  {
     if (rgx.Match(item).Success)
     list1.Add(item);
  }

Answer 3

With LINQ + regex, you can use this:

list = list.Where(s => Regex.IsMatch(s, "^[\\p{L}0-9]*$")).ToList();

^[\\p{L}0-9]*$ can recognise Unicode alphanumeric characters. If you want to use ASCII only, ^[a-zA-Z0-9]*$ will work just as well.