[c#] Remove all whitespace from C# string with regex

I am building a string of last names separated by hyphens. Sometimes a whitespace gets caught in there. I need to remove all whitespace from end result.

Sample string to work on:

Anderson -Reed-Smith

It needs to end up as (no space after Anderson):

Anderson-Reed-Smith

The last name string is in a string variable, LastName.

I am using a regular expression:

Regex.Replace(LastName, @"[\s+]", "");

The result of this is:

Anderson -Reed-Smith.

I also tried:

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

and

Regex.Replace(LastName, @"\s", "");

What am I doing wrong?

Using REGEX you can remove the spaces in a string.

The following namespace is mandatory.

using System.Text.RegularExpressions;

Syntax:

Regex.Replace(text, @"\s", "")

Fastest and general way to do this (line terminators, tabs will be processed as well). Regex powerful facilities don't really needed to solve this problem, but Regex can decrease performance.

                       new string
                           (stringToRemoveWhiteSpaces
                                .Where
                                (
                                    c => !char.IsWhiteSpace(c)
                                )
                                .ToArray<char>()
                           )

OR

                       new string
                           (stringToReplaceWhiteSpacesWithSpace
                                .Select
                                (
                                    c => char.IsWhiteSpace(c) ? ' ' : c
                                )
                                .ToArray<char>()
                           )

No need for regex. This will also remove tabs, newlines etc

var newstr = String.Join("",str.Where(c=>!char.IsWhiteSpace(c)));

WhiteSpace chars : 0009 , 000a , 000b , 000c , 000d , 0020 , 0085 , 00a0 , 1680 , 180e , 2000 , 2001 , 2002 , 2003 , 2004 , 2005 , 2006 , 2007 , 2008 , 2009 , 200a , 2028 , 2029 , 202f , 205f , 3000.

Below is the code that would replace the white space from the file name into given URL and also we can remove the same by using string.empty instead of "~"

  if (!string.IsNullOrEmpty(url))
          {
           string origFileName = Path.GetFileName(url);
           string modiFileName = origFileName.Trim().Replace(" ", "~");
           url = url.Replace(origFileName , modiFileName );
          }
          return url;

Why use Regex when you can simply use the Trim() method

Text='<%# Eval("FieldDescription").ToString().Trim() %>'

OR

string test = "Testing    ";
test.Trim();

Regex.Replace does not modify its first argument (recall that strings are immutable in .NET) so the call

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

leaves the LastName string unchanged. You need to call it like this:

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

All three of your regular expressions would have worked. However, the first regex would remove all plus characters as well, which I imagine would be unintentional.