Question

I have never got my head around using regular expressions, so I have a bit of an issue understanding why my below listed regex. doesn’t only allow the below listed characters:

• A-Z & a-z (upper & lower)
• ÅÄÖ & åäö
• 0-9 & _ (underscore)

Here’s the regex:

/^[\s\da-0-9-zA-ZåäöÅÄÖ_]$/i

What am I doing wrong?

Answer 1

Because this a-0-9-z is in reverse order. Use this: ^[\s\da-zA-ZåäöÅÄÖ_]$ or this: (?i)^[\s\da-zåäö_]$ with ignore case option set to enabled.

Also you can use special character \w, which means: letters, digits, and underscores

In you regex you’re using \d and 0-9. \d includes 0-9, see Explanation