Question

I need an regex to my preg_match(), it should preg (allow) the following characters:

String can contain only letters, numbers, and the following punctuation marks:

• full stop (.)
• comma (,)
• dash (-)
• underscore (_)

I have no idea , how it can be done on regex, but I think there is a way!

Answer 1

^[\p{L}\p{N}.,_-]*$

will match a string that contains only (Unicode) letters, digits or the “special characters” you mentioned. [...] is a character class, meaning “one of the characters contained here”. You’ll need to use the /u Unicode modifier for this to work:

preg_match(`/^[\p{L}\p{N}.,_-]*$/u', $mystring);

If you only care about ASCII letters, it’s easier:

^[\w.,-]*$

or, in PHP:

preg_match(`/^[\w.,-]*$/', $mystring);