regex check for white space in middle of string

Question

I want to validate that the characters are alpha numeric:

Regex aNum = Regex(\"[a-z][A-Z][0-9]\");

I want to add the option that there migh

Answer 1

To not allow empty strings then

Regex.IsMatch(s ?? "",@"^[\w\s]+$"); 

and to allow empty strings

Regex.IsMatch(s ?? "",@"^[\w\s]*$"); 

I added the ?? "" as IsMatch does not accept null arguments