A shorter way to run a match on the array's keys rather than the values:
<?php
function preg_grep_keys($pattern, $input, $flags = 0) {
return array_intersect_key($input, array_flip(preg_grep($pattern, array_keys($input), $flags)));
}
?>
preg_grep
(PHP 4, PHP 5, PHP 7)
preg_grep — Retourne un tableau avec les résultats de la recherche
Description
preg_grep
( string
$pattern
, array $input
[, int $flags = 0
] ) : array
preg_grep() retourne un tableau qui contient
les éléments de input
qui satisfont le masque pattern.
Liste de paramètres
-
pattern -
Le motif à chercher, sous la forme d'une chaîne de caractères.
-
input -
Le tableau d'entrée.
-
flags -
Si cette option vaut
PREG_GREP_INVERT, cette fonction retourne les éléments du tableauinputqui ne correspondent pas au motifpattern.
Valeurs de retour
Retourne un tableau indexé, en utilisant les clés du
tableau input d'entrée.
Exemples
Exemple #1 Exemple avec preg_grep()
<?php
// Recherche les nombres à virgule flottante dans le tableau
$fl_array = preg_grep("/^(\d+)?\.\d+$/", $array);
?>
Voir aussi
- Les Patterns PCRE
- preg_quote() - Protection des caractères spéciaux des expressions rationnelles
- preg_match_all() - Expression rationnelle globale
- preg_filter() - Recherche et remplace avec une expression rationnelle
- preg_last_error() - Retourne le code erreur de la dernière expression PCRE exécutée
add a note
User Contributed Notes 6 notes
Daniel Klein ¶
6 years ago
amolocaleb at gmail dot com ¶
8 months ago
This may be obvious to most experienced developers,but just in case its not,when using preg_grep to check for whitelisted items ,one must be very careful to explicitly define the regex boundaries or it will fail
<?php
$whitelist = ["home","dashboard","profile","group"];
$possibleUserInputs = ["homd","hom","ashboard","settings","group"];
foreach($possibleUserInputs as $input)
{
if(preg_grep("/$input/i",$whitelist)
{
echo $input." whitelisted";
}else{
echo $input." flawed";
}
}
?>
This results in:
homd flawed
hom whitelisted
ashboard whitelisted
settings flawed
group whitelisted
I think this is because if boundaries are not explicitly defined,preg_grep looks for any instance of the substring in the whole array and returns true if found.This is not what we want,so boundaries must be defined.
<?php
foreach($possibleUserInputs as $input)
{
if(preg_grep("/^$input$/i",$whitelist)
{
echo $input." whitelisted";
}else{
echo $input." flawed";
}
}
?>
this results in:
homd flawed
hom flawed
ashboard flawed
settings flawed
group whitelisted
in_array() will also give the latter results but will require few tweaks if say,the search is to be case insensitive,which is always the case 70% of the time
keithbluhm at gmail dot com ¶
9 years ago
Run a match on the array's keys rather than the values:
<?php
function preg_grep_keys( $pattern, $input, $flags = 0 )
{
$keys = preg_grep( $pattern, array_keys( $input ), $flags );
$vals = array();
foreach ( $keys as $key )
{
$vals[$key] = $input[$key];
}
return $vals;
}
?>
Anonymous ¶
8 months ago
- Add `filterKeys()`, because now only `filter()` (by values) exists.
- Add `anchored()` method (or other way) to use anchored patterns.
- Add a way to replace multiple strings with multiple replacements with one call to `preg_replace()`.
- Except from `filter()`/`filterKeys()`, add `except()`/`exceptKeys()` to filter out entries that match.
Timo Klemm ¶
2 years ago
An even shorter way to run a match on the array's keys rather than the values:
<?php
function preg_grep_keys($pattern, $input, $flags = 0) {
return array_flip( preg_grep($pattern, array_flip($input), $flags ) );
}
?>
vickyssj7 at gmail dot com ¶
4 years ago
A very simple example to match multiple "."(dot) in an array value:-
<?php
$array = array("23.32","22","12.009","23.43.43");
print_r(preg_grep("/^(\d+)?\.\d+\.\d+$/",$array));
?>
