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?

Answer 1

Instead of a RegEx use Replace for something that simple:

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

Answer 2

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.