preg_filter
(PHP 5 >= 5.3.0)
preg_filter — 执行一个正则表达式搜索和替换
说明
$pattern
, mixed $replacement
, mixed $subject
[, int $limit = -1
[, int &$count
]] )preg_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.
返回值
如果subject是一个 数组 ，返回一个 数组 ，
其他情况返回一个 字符串 。
如果没有找到匹配或者发生了错误，当subject是 数组
时返回一个空 数组 ，其他情况返回 NULL 。
范例
Example #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 , $subject ));
?> 以上例程会输出：
preg_filter returns
Array
(
[0] => A:C:1
[1] => B:C:a
[2] => A:2
[3] => B:b
[4] => A:3
[7] => A:4
)
preg_replace returns
Array
(
[0] => A:C:1
[1] => B:C:a
[2] => A:2
[3] => B:b
[4] => A:3
[5] => A
[6] => B
[7] => A:4
)
参见
- PCRE Patterns
- preg_replace() - 执行一个正则表达式的搜索和替换
- preg_replace_callback() - 执行一个正则表达式搜索并且使用一个回调进行替换
- preg_grep() - 返回匹配模式的数组条目
- preg_last_error() - 返回最后一个PCRE正则执行产生的错误代码
用户评论:
[#1] fgmhhfg at gmail dot com [2014-03-04 10:44:55]
As for the php 5.5.3 version, the example turn out like:
Array
(
[0] => A:1
[1] => B:a
...
)
[#2] Anonymous [2014-03-04 10:36:07]
As for the php 5.5.3 version, the example will turn out like:
Array
(
[0]=>A:1
[1]=>B:a
...
)
[#3] sajina_99 at hotmail dot de [2011-09-25 07:07:08]
As I had to work with PHP5.2.X and needed preg_filter I wrote a quick and dirty workaround.
<?php
if (!function_exists('preg_filter')) {
function preg_filter($pattern, $replace, $subject, $limit = -1 , &$count = null) {
if(!is_array($subject)) {
$noArray = 1 ;
$subject = array($subject);
}
$preg = preg_replace($pattern, $replace, $subject, $limit, &$count);
$diff = array_diff($preg, $subject);
if($noArray == 1) $diff = implode($diff) ;
return $diff ;
}
}
?>
[#4] MrBertie [2010-12-31 02:35:15]
Another way to filter an array, and simply return the matching items: preg_grep!