How to remove characters from a string, except those in a list

Question

This is my string value:

string str = \"32 ab d32\";

And this list is my allowed characters:

var allowedCharacters = new List&l         


        

Answer 1

Regex? Regex may be overkill for what you're trying to accomplish.

Here's another variation without regex (modified your lstAllowedCharacters to actually be an enumerable of characters and not strings [as the variable name implies]):

String original = "32 ab d32";
Char replacementChar = ' ';
IEnumerable allowedChars = new[]{ 'a', 'b', 'c', '2', ' ' };

String result = new String(
  original.Select(x => !allowedChars.Contains(x) ? replacementChar : x).ToArray()
);