How can I validate a string to only allow alphanumeric characters in it?

Question

How can I validate a string using Regular Expressions to only allow alphanumeric characters in it?

(I don\'t want to allow for any spaces either).

Answer 1

Use the following expression:

^[a-zA-Z0-9]*$

ie:

using System.Text.RegularExpressions;

Regex r = new Regex("^[a-zA-Z0-9]*$");
if (r.IsMatch(SomeString)) {
  ...
}