PHP正则表达式

<?php
error_reporting(E_ALL); //报告所有错误，error_reporting(0)设置会忽略错误

//与perl里面的正则类似，/****/i,//为正则表达式界定符，js也可这样表示
$regex = '/^http:\/\/([\w.]+)\/([\w]+)\/([\w]+)\.html$/i';
$str = 'http://www.youku.com/show_page/id_ABCDEFG.html';
$matches = array();

if(preg_match($regex, $str, $matches)){
var_dump($matches);
}

echo "<br/>";
$reg = '/(?<num>\d+)/i';
$k = "asd33sdfds4434dsdfd2222";
$m_array = array();
//匹配所有的
if(preg_match_all($reg, $k, $m_array))
{
var_dump($m_array);
}

//将连续的数字替换为一个*
$a = preg_replace('/(\d+)/i', '*', 'asd3343ddsf999dfdf000fff');
echo "<br/>".$a;

//用,.;符号分割字符
$sv = preg_split('/[,\.;]/i', "aa,dd;xxx.sdsd");
var_dump($sv);
?>