How do I match accented characters with PHP preg?

Question

I’d like to give my users the option to not only fill in letters and numbers, but also “special” letters like the “á”, “é”, etc. However, I do not want them to be able to us

Answer 1

You could use Unicode character properties to describe the characters:

/^[\p{L}-]*$/u

\p{L} describes the class of Unicode letter characters.