Filter @mentions and #hashtags from a string

filter.php

<?php
/**
 * Filter @mentions and #hashtags from a string
 *
 * @author saiik<saikon@hotmail.de>
 * @license GPLv3
 */

$str = 'Hello @saiik! #php #github';

preg_match_all('/@\w+/', $str, $mentions);
preg_match_all('/#\w+/', $str, $hashtags);

var_dump($mentions);
var_dump($hashtags);