我的测试代码示例：
<?
$city = "L'u00e9ry, Quebec";
echo 'city original: '.$city.'<br>';
$city = preg_replace('/u(['da-fA-F]{4})/', '&#x'1;', $city);
echo 'city modified: '.$city.'<br>';
?>
我的结果是：
city original: L'u00e9ry, Quebec
city modified: L'éry, Q
我遇到了一些问题...感谢
这应该适合您：
$city = preg_replace('/''''u([0-9a-fA-F]{4})/', '&#x'1;', $city);
输出：
city original: L'u00e9ry, Quebec
city modified: Léry, Quebec