how to allow apostrophes in regular expressions in php [closed]

Answer 1

You should not use htmlentities before checking your strings, you may use it after.

If you apply $name = htmlentities($name, ENT_QUOTES, "UTF-8"); to some'name, it will turn into some'name.

Also, to shorten the pattern, use

preg_match("/^[A-Z'-]{2,50}$/i", $name)

The /i case insensitive modifier will make the whole pattern case insensitive, and [A-Z] will match all upper- and lowercase ASCII letters.