php【基础练习十二】正则表达式

<?php/** * Created by PhpStorm. * User: dell * Date: 2015/12/28 * Time: 11:46 */$regex = '/^http:\/\/([\w.]+)\/([\w]+)\/([\w]+)\.html$/i';$str = 'http://www.youku.com/show_page/id_ABCDEFG.html';$matches = array();if(preg_match($regex, $str, $matches)){    var_dump($matches);}echo '<br>';echo '<br>';$regex = '/HELLO/';$str = 'hello word';$matches = array();if(preg_match($regex, $str, $matches)){    echo 'No i:Valid Successful!',"\n";}if(preg_match($regex.'i', $str, $matches)){//这里的i表示忽略大小写    echo 'YES i:Valid Successful!',"\n";}