How to remove WeChat emoticons in php

  protected function emoji_filter($str) {
        if($str){
            $name = $str;
            $name = preg_replace('/\xEE[\x80-\xBF][\x80-\xBF]|\xEF[\x81-\x83][\x80-\xBF]/', '', $name);
            $name = preg_replace('/xE0[x80-x9F][x80-xBF]‘.‘|xED[xA0-xBF][x80-xBF]/S','?', $name);
            $return = json_decode(preg_replace("#(\\\ud[0-9a-f]{3})#ie","",json_encode($name)));
 
        }else{
            $return = '';
        }
        return $return;
 
    }