preg_filter

Perform a regular expression search and replace

Description

mixed preg_filter ( mixed $pattern , mixed $replacement , mixed $subject [, int $limit = -1 [, int &$count ]] )

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.

Return Values

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.

Examples

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)); 
?>

The above example will output:

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
)

See Also

  • PCRE Patterns
  • preg_quote
  • preg_replace
  • preg_replace_callback
  • preg_grep
  • preg_last_error