If you use exchangeArray method of ArrayObject and then next method of ArrayIterator like this:
<?php
$fruits = array("apple", "grape", "lemon");
$colors = array("blue", "yellow", "green");
$arrayObject = new ArrayObject($fruits);
$arrayIterator = $arrayObject->getIterator();
while($arrayIterator->valid()) {
if ($arrayIterator->current() == "grape") {
$arrayObject->exchangeArray($colors);
}
$arrayIterator->next();
}
?>
You will receive:
PHP Notice: ArrayIterator::next(): Array was modified outside object and internal position is no longer valid
So be careful with next and prev operations. :)