PHP Convert String to SEO Friendly Url For Bengali Language Type

Question

I wanted to covert the string into a friendly url

 function seo_url( $string, $separator = '-' )
 {
   $accents_regex = '~&([a-z]{1,2})(?:acute|cedil|circ|grave|lig|orn|ring|slash|th|tilde|uml);~i';
   $special_cases = array( '&' => 'and', "'" => '');
   $string = mb_strtolower( trim( $string ), 'UTF-8' );
   $string = str_replace( array_keys($special_cases), array_values( $special_cases), $string );
   $string = preg_replace( $accents_regex, '$1', htmlentities( $string, ENT_QUOTES, 'UTF-8' ) );
   $string = preg_replace("/[^a-z0-9]/u", "$separator", $string);
   $string = preg_replace("/[$separator]+/u", "$separator", $string);
   return $string;
 } 

 I used this code for that It worked for english but not working for bengali language 

Answer 1

$string = preg_replace("/[^a-z0-9]/u", "$separator", $string);  change the regex in this line of code
$string = preg_replace("/[^\p{L}\p{M}]/u", "$separator", $string); try this instead and it will work