array_find_key

(PHP 8 >= 8.4.0)

array_find_keyReturns the key of the first element satisfying a callback function

Description

array_find_key(array $array, callable $callback): mixed

array_find_key() returns the key of the first element of an tableau for which the given callback returns true. If no matching element is found the function returns null.

Liste de paramètres

array
The tableau that should be searched.
callback

The callback function to call to check each element, which must be

callback(mixed $value, mixed $key): bool
If this function returns true, the key is returned from array_find_key() and the callback will not be called for further elements.

Valeurs de retour

The function returns the key of the first element for which the callback returns true. If no matching element is found the function returns null.

Exemples

Exemple #1 array_find_key() example

<?php
$array
= [
'a' => 'dog',
'b' => 'cat',
'c' => 'cow',
'd' => 'duck',
'e' => 'goose',
'f' => 'elephant'
];

// Find the first animal with a name longer than 4 characters.
var_dump(array_find_key($array, function (string $value) {
return
strlen($value) > 4;
}));

// Find the first animal whose name begins with f.
var_dump(array_find_key($array, function (string $value) {
return
str_starts_with($value, 'f');
}));

// Find the first animal where the array key is the first symbol of the animal.
var_dump(array_find_key($array, function (string $value, $key) {
return
$value[0] === $key;
}));

// Find the first animal where the array key matching a RegEx.
var_dump(array_find_key($array, function ($value, $key) {
return
preg_match('/^([a-f])$/', $key);
}));
?>

L'exemple ci-dessus va afficher :

string(1) "e"
NULL
string(1) "c"
string(1) "a"

Voir aussi

  • array_find() - Returns the first element satisfying a callback function
  • array_all() - Checks if all tableau elements satisfy a callback function
  • array_any() - Checks if at least one tableau element satisfies a callback function
  • array_filter() - Filtre les éléments d'un tableau grâce à une fonction de rappel
  • array_reduce() - Réduit itérativement un tableau
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