PHP - Check if two arrays are equal

I'd like to check if two arrays are equal. I mean: same size, same index, same values. How can I do that? Using `!==` as suggested by a user, I expect that the following would print **enter** if at least one element in the array(s) are different, but in fact it does not. if (($_POST['atlOriginal'] !== $oldAtlPosition) or ($_POST['atl'] !== $aext) or ($_POST['sidesOriginal'] !== $oldSidePosition) or ($_POST['sidesOriginal'] !== $sideext)) { echo "enter"; }