iterator_apply
Be careful of thinking of iterators and arrays as completely analogous in your PHP code. iterator_count will NOT return your iterator to its previous state after looping through it for the count. Any iterator implementation that also implements Countable::count isn't required to do so either.
This is clearest in example form:
<?php
$array = array(
1 => 'foo',
2 => 'bar'
);
foreach ($array as $key => $value)
{
echo "$key: $value (", count($array), ")\n";
}
$iterator = new ArrayIterator($array);
foreach ($iterator as $key => $value)
{
echo "$key: $value (", iterator_count($iterator), ")\n";
}
?>
outputs:
1: foo (2)
2: bar (2)
1: foo (2)
Notice that because of how iterator_count works we never see the second iterator value because the next call to then Iterator::valid() implementation returns false (its at the end of the iterator).
iterator_count
(PHP 5 >= 5.1.0)
iterator_count — Compte de nombre d'éléments dans un itérateur
Description
Avertissement
Cette fonction n'est pas documentée et seule la liste des arguments est disponible.
Compte les éléments dans un itérateur.
Liste de paramètres
- iterator
-
L'itérateur dont il faut compter les éléments.
Valeurs de retour
Le nombre d'éléments dans l'itérateur iterator .
Exemples
Exemple #1 Exemple avec iterator_count()
<?php
$iterator = new ArrayIterator(array('recipe'=>'crêpes', 'oeufs', 'lait', 'farine'));
var_dump(iterator_count($iterator));
?>
L'exemple ci-dessus va afficher :
int(4)
add a note
User Contributed Notesiterator_count
donovan jimenez
23-Feb-2009 06:34
23-Feb-2009 06:34
Micha Mech
09-May-2008 12:38
09-May-2008 12:38
Yes, but ...
Traversable: "Abstract base interface that cannot be implemented alone. Instead it must be implemented by either IteratorAggregate or Iterator."
So You have to implement IteratorAggregate or Iterator because You can not implement Traversable.
Ard
31-Aug-2006 12:39
31-Aug-2006 12:39
Note that you that the iterator parameter doesn't need to be of type Aggregate. As the spl documentation on http://www.php.net/~helly/php/ext/spl/ defines it in the following way:
iterator_count (Traversable $it).
So you can count the number of files in a given directory quite easily:
<?php iterator_count(new DirectoryIterator('path/to/dir/')); ?>