Since PHP 5.5.X foreach can accept non scalar items. So the return can be anything ;)
Iterator::key
(PHP 5, PHP 7, PHP 8)
Iterator::key — Retourne la clé de l'élément courant
Liste de paramètres
Cette fonction ne contient aucun paramètre.
Valeurs de retour
Retourne un scalaire en cas de succès, ou
null si une erreur survient.
Erreurs / Exceptions
Émet une alerte de type E_NOTICE si une erreur survient.
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User Contributed Notes 3 notes
michaelgranados at gmail dot com ¶
11 years ago
Lszl Lajos Jnszky ¶
12 years ago
And converts everything to integer except string, so in php the post process could be:
public function key() {
$yourKey = $this->createYourKey();
if (is_object($yourKey) || is_array($yourKey))
throw new Exception('Array and Object not allowed.');
elseif (is_string($yourKey))
return $yourKey;
else
return (int) $yourKey;
}
sofe2038 at gmail dot com ¶
4 years ago
This function may return any type, not just scalar, for some Iterator types. In particular, it is very trivial to write a generator function that yields arbitrary keys:
<?php
function foo() {
yield null => 1;
yield new stdclass => 2;
}
?>
