How to change rewrite this code to use preg_replace_callback

Question

return preg_replace('/[\xC0-\xF7][\x80-\xBF]/e', 'mb2entity("\0")', $str);

Answer 1

return preg_replace_callback('/[\xC0-\xF7][\x80-\xBF]/', function($n1) { return mb2entity($n1); }, $str);