Since PHP 5.5.X foreach can accept non scalar items. So the return can be anything ;)
(PHP 5, PHP 7, PHP 8)
Iterator::key — Return the key of the current element
This function has no parameters.
Returns scalar on success, or null on failure.
Issues E_NOTICE on failure.
Since PHP 5.5.X foreach can accept non scalar items. So the return can be anything ;)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;
}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;
}
?>