<?
$array = array(array("a", "b"), array("c", "d"));

foreach ($array[1] as $key=>$value) {
	echo "Foreach cycle: ", $key, "=>", $value, "\n";
}

reset($array);  // Resets only the external array
// reset($array[1]);  // Resets $array[1] itself

while (list($key, $value) = each($array[1])) {
	echo "While cycle: ", $key, "=>", $value, "\n";
}
?>

The internal pointer of $array[1] is at the end of the array, so no output will be produced from the second cycle. I have to reset($array[1]), if I want it to be reset.

This is submitted once as a bug:
http://bugs.php.net/bug.php?id=37

I agree that it's the right behaviour of reset(), but if I want to explicitely reset all the sub-arrays of an array, I have to write too complicated cycles + condition checks, for such a basic thing like this.

It will be nice to have the option somewhere in the future (maybe as a second optional parameter) to reset all the internal arrays at once. ;)