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

Try this:

string srVariable = "32 ab d32";
List lstAllowedCharacters = new List { "a", "b", "c", "2", " " };

srVariable = Regex.Replace(srVariable, "[^" + Regex.Escape(string.Join("", lstAllowedCharacters) + "]"), delegate(Match m)
{
    if (!m.Success) { return m.Value; }
    return " ";
});

Console.WriteLine(srVariable);