.NET RegEx for letters and spaces

Question

I am trying to create a regular expression in C# that allows only alphanumeric characters and spaces. Currently, I am trying the following:

string pattern = @"^\w+$";
Regex regex = new Regex(pattern);
if (regex.IsMatch(value) == false)
{
  // Display error
}

What am I doing wrong?

Answer 1

Try this Regex: "^[0-9A-Za-z ]+$"

The brackets specify a set of characters

0-9: All digits

A-Z: All capital letters

a-z: All lowercase letters

' ': Spaces

Do you need non A-Z letters checked?

Answer 2

The character class \w does not match spaces. Try replacing it with [\w ] (there's a space after the \w to match word characters and spaces. You could also replace the space with \s if you want to match any whitespace.

Answer 3

If, other then 0-9, a-z and A-Z, you also need to cover any accented letters like ï, é, æ, Ć or Ş then you should better use the Unicode properties \p{...} for matching, i.e. (note the space):

string pattern = @"^[\p{IsLetter}\p{IsDigit} ]+$";