Regex for removing only specific special characters from string

Question

I\'d like to write a regex that would remove the special characters on following basis:

• To remove white space character
• @, &

Answer 1

 string username = Regex.Replace(_username, @"(\s+|@|&|'|\(|\)|<|>|#)", "");

Answer 2

I suggest using Linq instead of regular expressions:

 string source = ...

 string result = string.Concat(source
   .Where(c => !char.IsWhiteSpace(c) && 
                c != '(' && c != ')' ...));

In case you have many characters to skip you can organize them into a collection:

 HashSet<char> skip = new HashSet<char>() {
   '(', ')', ... 
 };

 ... 

 string result = string.Concat(source
   .Where(c => !char.IsWhiteSpace(c) && !skip.Contains(c)));

Answer 3

use a character set [charsgohere]

string removableChars = Regex.Escape(@"@&'()<>#");
string pattern = "[" + removableChars + "]";

string username = Regex.Replace(username, pattern, "");

Answer 4

You can easily use the Replace function of the Regex:

string a = "ash&#<>fg  fd";
a= Regex.Replace(a, "[@&'(\\s)<>#]","");