Remove all whitespace from C# string with regex

Question

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?

You don't need regex if the name is the only data in the string. Otherwise you can probably use ( -|- | - ) — Evo510
– Evo510, Commented May 2, 2013 at 19:29

Gabe · Accepted Answer · 2013-05-02 19:27:29Z

142

Instead of a RegEx use Replace for something that simple:

LastName = LastName.Replace(" ", String.Empty);

answered May 2, 2013 at 19:27

Gabe

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6 Comments

Geeky Guy Over a year ago

This. I would vote this answer up right now, but I've reached my voting limit for today.

Julián Urbano Over a year ago

Didn't know there was a limit!

maxwellb Over a year ago

But not with tabs or other whitespace characters other than space (ordinal 32).

Gabe Over a year ago

@maxwellb - From the OP, it looks like they are only dealing with "spaces"

BattlFrog Over a year ago

Not sure what the deal was, I tried the above and it still didn't work, then I removed an earlier call to .Trim, then it started working. I guess it didnt like looking at the same thing twice. Either way, I am good to go now.

|

Sergey Kalinichenko · Accepted Answer · 2013-05-02 19:35:51Z

70

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.

answered May 2, 2013 at 19:35

Sergey Kalinichenko

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1 Comment

Ishikawa Over a year ago

This should be the correct answer to the original question.

I4V · Accepted Answer · 2013-05-02 19:50:42Z

14

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.

edited May 2, 2013 at 19:50

answered May 2, 2013 at 19:27

I4V

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3 Comments

Julián Urbano Over a year ago

Have a problem. Want to solve it with regex. Now I have two problems. Solve it with LINQ. Still two problems :-)

I4V Over a year ago

@JuliánUrbano Yes Regex can be a problematic while maintaining, but I can't say the same for Linq.

Moo-Juice Over a year ago

@JuliánUrbano, you should never want to solve anything because it is a particular API. Far too many questions are answered on this site with a LINQ answer, even though - in essence - it can be solved far more easily and far quicker. Pick the best solution.

CSharpCoder · Accepted Answer · 2017-07-26 14:37:37Z

3

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>()
                           )

edited Jul 26, 2017 at 14:37

answered Jul 24, 2017 at 11:51

CSharpCoder

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4 Comments

Jerren Saunders Over a year ago

FYI, I did a benchmark test between the first code snipped here (stringToRemoveWhiteSpaces) and the String.Join code posted by I4V and you new String(stringToRemoveWhiteSpaces...) code ran about 40% faster.

ilasno Over a year ago

@JerrenSaunders But what about compared with the Regex solution? :-D

Jerren Saunders Over a year ago

I can't say I tested the regex solution. I tend to agree with CSharpCoder's comments in this answer that the overhead of regex can sometimes be too much for the more simple task. That said, to be fair I should not make that assumption without including it in a benchmark.

Jerren Saunders Over a year ago

The benchmark results when performing each operation 10M times: The first snippet here (.Where): 10813 ticks, I4V's Join/Where: 13140 ticks, dasblinkenlight's Regex.Replace: 22969 ticks, and Gabe's accepted answer's: 1297 ticks.

pramod · Accepted Answer · 2019-06-03 10:15:44Z

1

Using REGEX you can remove the spaces in a string.

The following namespace is mandatory.

using System.Text.RegularExpressions;

Syntax:

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

answered Jun 3, 2019 at 10:15

pramod

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Comments

Paul Alexeev · Accepted Answer · 2021-03-27 21:30:27Z

0

You can write so, for exaple with phone number:

private static string GetFormattedPhoneNumber(string phoneNumber)
    => string.IsNullOrEmpty(phoneNumber) ? string.Empty 
    : Regex.Replace(phoneNumber, @"[+,\-,\(,\), \s+]*", string.Empty);

static void Main(string[] args)
    {
       Console.WriteLine(GetFormattedPhoneNumber("+375 (24) 55-333 "));
    }
/*
    Output: 3752455333
*/

answered Mar 27, 2021 at 21:30

Paul Alexeev

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Comments

Pooja Rawat · Accepted Answer · 2022-07-20 05:56:19Z

0

In my case, I have you remove whitespaces:

   var year = System.Text.RegularExpressions.Regex.Replace(space, @"&nbsp;", string.Empty).Replace("Year: ", string.Empty).Trim();

answered Jul 20, 2022 at 5:56

Pooja Rawat

1

Comments

user7329414 · Accepted Answer · 2016-12-22 09:14:15Z

-2

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;

edited Dec 22, 2016 at 9:14

answered Dec 22, 2016 at 8:37

user7329414

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1 Comment

Drag and Drop Over a year ago

Op said " I need to remove all whitespace" and used \s. But this handle only " " space and is mostly not related. While Trim() handles only leading and trailling space. I don't see fit.

Tom McDonough · Accepted Answer · 2017-02-07 14:12:47Z

-3

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

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

OR

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

answered Feb 7, 2017 at 14:12

Tom McDonough

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1 Comment

Gianpiero Over a year ago

He requires removing all spaces not just leading and ending spaces

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