Best way to get all digits from a string [duplicate]

Answer 1

In perl (you can adapt this to C#) simply do

$str =~ s/[^0-9]//g; 

I am assuming that your string is in $str. Basic idea is to replace all non digits with '' (i.e. empty string)

Answer 2

Just remove all non-digits:

var result = Regex.Replace(input, @"\D", "");

Answer 3

Have you got something against Replace?

return Regex.Replace(input, @"[^0-9]+", "");

Answer 4

Do you need to use a Regex?

return new String(input.Where(Char.IsDigit).ToArray());

Answer 5

You'll want to replace /\D/ (non-digit) with '' (empty string)

Regex r = new Regex(@"\D");
string s = Regex.Replace("(123) 455-2344", r, "");

Or more succinctly:

string s = Regex.Replace("(123) 455-2344", @"\D",""); //return only numbers from string