(PHP 5 >= 5.3.0, PHP 7, PHP 8)
preg_filter — 执行一个正则表达式搜索和替换
$pattern,$replacement,$subject,$limit = -1,&$count = nullpreg_filter()等价于preg_replace() 除了它仅仅返回(可能经过转化)与目标匹配的结果. 这个函数怎样工作的更详细信息请阅读 preg_replace()文档.
preg_replace() 文档中描述了参数。
如果传递的正则表达式无法正常解析，会发出 E_WARNING。
示例 #1 比较preg_filter() 和preg_replace()的示例
<?php
$subject = array('1', 'a', '2', 'b', '3', 'A', 'B', '4');
$pattern = array('/\d/', '/[a-z]/', '/[1a]/');
$replace = array('A:$0', 'B:$0', 'C:$0');
echo "preg_filter returns\n";
print_r(preg_filter($pattern, $replace, $subject));
echo "preg_replace returns\n";
print_r(preg_replace($pattern, $replace, $subject));
?>以上示例会输出：
preg_filter returns
Array
(
[0] => A:C:1
[1] => B:C:a
[2] => A:2
[3] => B:b
[4] => A:3
[7] => A:4
)
preg_replace returns
Array
(
[0] => A:C:1
[1] => B:C:a
[2] => A:2
[3] => B:b
[4] => A:3
[5] => A
[6] => B
[7] => A:4
)