(PHP 5 >= 5.3.0, PHP 7, PHP 8)
preg_filter — Perform a regular expression search and replace
$pattern,$replacement,$subject,$limit = -1,&$count = 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.
Parameters are described in the documentation for preg_replace() .
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.
If the regex pattern passed does not compile to a valid regex, an E_WARNING is emitted.
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]/');
$replace = array('A:0ドル', 'B:0ドル', 'C:0ドル');
echo "preg_filter returns\n";
print_r(preg_filter($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 )
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ドル', 'Б:0ドル', 'В:0ドル');
?>If you don't want to actually replace the matches, just filter the array to them, make the replacement parameter '0ドル'.
<?php
$subject = array('1', 'a', '2', 'b', '3', 'A', 'B', '4');
$result = preg_filter('/\d/', '0ドル', $subject); // ['1','2','3','4']
?>As I had to work with PHP5.2.X and needed preg_filter I wrote a quick and dirty workaround.
<?php
if (!function_exists('preg_filter')) {
function preg_filter($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 ;
}
}
?>