Question

I’m trying to add the character Ö (U+00D6) to my regular expression below. Apparently something is going wrong because it’s not working on my preg_match function.

The regular expression that works fine:

/^([A-Z]{1})[a-z]{1,31}$/

The one that should work but does not:

/^([A-Z\x{00D6}]{1})[a-z]{1,31}$/

I’m obviously trying to create a regular expression that is started with an uppercase letter extended with Ö and followed by lowercase letters. In total, the length of the string must be between 2-32. What is wrong with the regular expression that contains the Unicode expression for Ö?

Answer 1

The \x{00D6} will only match the single byte \xD6 symbol. When you pass in a string to preg_match it’s however most likely encoded in UTF-8, which is \xC3 \x96.

You need to use the /u modifier for your regex to support that.

/^([A-Z\x{00D6}]{1})[a-z]{1,31}$/u

Also the {1} is decorative, but redundant.