preg_filter

(PHP 5 >= 5.3.0, PHP 7)

preg_filterPerform a regular expression search and replace

Descrierea

preg_filter ( string|array $pattern , string|array $replacement , string|array $subject , int $limit = -1 , int &$count = null ) : string|array|null

preg_filter() is identical to preg_replace() except it only returns the (possibly transformed) subjects where there was a match. For details about how this function works, read the preg_replace() documentation.

Valorile întoarse

Returns an array if the subject parameter is an array, or a string otherwise.

If no matches are found or an error occurred, an empty array is returned when subject is an array or null otherwise.

Exemple

Example #1 Example comparing preg_filter() with preg_replace()

<?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)); 
?>

Exemplul de mai sus va afișa:

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
)

A se vedea și

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User Contributed Notes 6 notes

up
10
forsoap at gmail dot com
8 years ago
For those who read manual not in English and figure out that example code returns not the same result as in documentation

You need put in example patter modifier "u" to get same result:

<?php
$subject
= array('1', 'а', '2', 'б', '3', 'А', 'Б', '4');
// Added "u"
$pattern = array('/\d/u', '/[а-я]/u', '/[1а]/u');
$replace = array('А:$0', 'Б:$0', 'В:$0');
?>
up
6
bienvenunet at yahoo dot com
7 years ago
If you don't want to actually replace the matches, just filter the array to them, make the replacement parameter '$0'.

<?php
$subject
= array('1', 'a', '2', 'b', '3', 'A', 'B', '4');
$result = preg_filter('/\d/', '$0', $subject);  // ['1','2','3','4']
?>
up
2
sajina_99 at hotmail dot de
13 years ago
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 ;
     
    }
   
  }
?>
up
-30
MrBertie
13 years ago
Another way to filter an array, and simply return the matching items: preg_grep!
up
-28
fgmhhfg at gmail dot com
10 years ago
As for the php 5.5.3 version, the example  turn out like:
Array
(
       [0] => A:1
       [1] => B:a
       ...
)
up
-39
Anonymous
10 years ago
As for the php 5.5.3 version, the example will turn out like:
Array
(
       [0]=>A:1
       [1]=>B:a
       ...
)
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