How to keep white spaces when using String.Concat

Question

To prevent the user from inputting anything besides letter or numbers, I am using

string.Concat(textbox.Text.Where(char.IsLetterOrDigit ));

However, I would like to prevent the Concat method from removing white spaces, and the Concat method does not take multiple arguments. Suggestions? Perhaps Regex would be smarter?

Answer 1

The space character isn't a letter or a digit so you need to change your Where clause, for examples:

string.Concat(textbox.Text.Where(c => char.IsLetterOrDigit(c) || c == ' '));

Answer 2

It's not the Concat that is removing whitespaces. Where is removing whitespaces, because whitespaces are neither letters not digits.

You just need to modify the Where:

string.Concat(textbox.Text.Where(x => char.IsLetterOrDigit(x) || char.IsWhiteSpace(x) ));

Since you mentioned regex, here is a regex to do it:

[^\p{L}\p{Nd}\s]

Regex.Replace the above with an empty string and you will get the result:

Regex.Replace(input, "[^\\p{L}\\p{Nd}\\s]", "")