One important thing to remember is that in iterator can be infinite. Not all iterators necessarily end. If iterator_to_array is used on such an iterator, it will exhaust the available memory, and throw a fatal error.
For example, consider the following code:
<?php
function fibonacci(): Generator
{
yield $a = 1;
yield $b = 2;
start:
yield $c = $a + $b;
$a = $b;
$b = $c;
goto start;
}
$fibonacciSequence = fibonacci();
iterator_to_array($fibonacciSequence);
?>
Since <?php fibonacci(); ?> generates an infinite fibonacci sequence, which is valid, since it is actually an infinite sequence, then attempting to convert it to an array will fail.
iterator_to_array
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
iterator_to_array — Copie un itérateur dans un tableau
Description
Copie les éléments d'un itérateur dans un tableau.
Liste de paramètres
-
iterator -
L'itérateur à copier.
-
preserve_keys -
S'il faut utiliser les éléments de l'itérateur comme clé.
Si une clé est un array ou un object, une alerte sera générée. Les clés
nullseront converties en une chaîne vide, les clés de type float seront tronquées en leurs parties int, les clés de type resource génèreront une alerte et seront converties en identifiant de la ressource, et les clés de type bool seront converties en entiers.Note:
Si ce paramètre n'est pas défini ou défini sur
true, les clés dupliquées seront écrasées. La dernière valeur avec une clé donnée sera dans le array retourné. Définir ce paramètre àfalsepour obtenir toutes les valeurs en tout cas.
Valeurs de retour
Un tableau contenant les éléments de l'itérateur
iterator.
Historique
| Version | Description |
|---|---|
| 8.2.0 |
Le type de iterator a été élargi de
Traversable à
Traversable|array.
|
Exemples
Exemple #1 Exemple avec iterator_to_array()
<?php
$iterator = new ArrayIterator(array('recipe'=>'crêpes', 'oeufs', 'lait', 'farine'));
var_dump(iterator_to_array($iterator, true));
var_dump(iterator_to_array($iterator, false));
?>L'exemple ci-dessus va afficher :
array(4) {
["recipe"]=>
string(7) "crêpes"
[0]=>
string(5) "oeufs"
[1]=>
string(4) "lait"
[2]=>
string(6) "farine"
}
array(4) {
[0]=>
string(7) "crêpes"
[1]=>
string(5) "oeufs"
[2]=>
string(4) "lait"
[3]=>
string(6) "farine"
}
add a note
User Contributed Notes 6 notes
wizzard351 at yahoo dot com ¶
2 years ago
jerome at yazo dot net ¶
16 years ago
Using the boolean param :
<?php
$first = new ArrayIterator( array('k1' => 'a' , 'k2' => 'b', 'k3' => 'c', 'k4' => 'd') );
$second = new ArrayIterator( array( 'k1' => 'X', 'k2' => 'Y', 'Z' ) );
$combinedIterator= new AppendIterator();
$combinedIterator->append( $first );
$combinedIterator->append( $second );
var_dump( iterator_to_array($combinedIterator, false) );
?>
will output :
array(7) (
[0]=>
string(1) "a"
[1]=>
string(1) "b"
[2]=>
string(1) "c"
[3]=>
string(1) "d"
[4]=>
string(1) "X"
[5]=>
string(1) "Y"
[6]=>
string(1) "Z"
)
<?php
var_dump( iterator_to_array($combinedIterator, true) );
?>
will output (since keys would merge) :
array(5) (
["k1"]=>
string(1) "X"
["k2"]=>
string(1) "Y"
["k3"]=>
string(1) "c"
["k4"]=>
string(1) "d"
[0]=>
string(1) "Z"
)
joksnet at gmail dot com ¶
10 years ago
To generate an deep array from nested iterators:
<?php
function iterator_to_array_deep(\Traversable $iterator, $use_keys = true) {
$array = array();
foreach ($iterator as $key => $value) {
if ($value instanceof \Iterator) {
$value = iterator_to_array_deep($value, $use_keys);
}
if ($use_keys) {
$array[$key] = $value;
} else {
$array[] = $value;
}
}
return $array;
}
?>
I use it to test an iterator: https://gist.github.com/jm42/cb328106f393eeb28751
Harry Willis ¶
9 years ago
When using iterator_to_array() on an SplObjectStorage object, it's advisable to set $use_keys to false.
The resulting array is identical, since the iterator keys produced by SplObjectStorage::key() are always integers from 0 to (COUNT-1). Passing $use_keys=false cuts out the unnecessary calls to SplObjectStorage::key(), giving a slight performance advantage.
chad 0x40 herballure 0x2e com ¶
16 years ago
The use_keys parameter was added in one of the 5.2.x releases; it defaults to TRUE. This matches the behavior in PHP 5.1.6, which lacks this parameter.
enelar at develop-project dot ru ¶
7 years ago
Generator approach
function scandir_deep($dir)
{
foreach (scandir($dir) as $key => $value)
if (in_array($value, [".",".."]))
continue;
else if (is_dir($dir . DIRECTORY_SEPARATOR . $value))
yield $value => scandir_deep($dir . DIRECTORY_SEPARATOR . $value);
else
yield $value;
}
