C# Regex to allow only alpha numeric

Question

I have the following regex ^[a-zA-Z0-9]+$ which would allow alpha numeric characters. The problem here is that if I enter only numeric character like \"897687\"

Answer 1

Just in case that the ASCII characters are at some point not enough, here the Unicode version:

^\p{L}[\p{L}\p{N}]*$

\p{L} is any Unicode code point that has the property letter ==> Any letter from any language (that is in Unicode)

\p{N} is any Unicode code point that has the property number ==> Any number character from any language (that is in Unicode)