Note that array_intersect and array_unique doesnt work well with multidimensional arrays.
If you have, for example,
<?php
$orders_today[0] = array('John Doe', 'PHP Book');
$orders_today[1] = array('Jack Smith', 'Coke');
$orders_yesterday[0] = array('Miranda Jones', 'Digital Watch');
$orders_yesterday[1] = array('John Doe', 'PHP Book');
$orders_yesterday[2] = array('Z? da Silva', 'BMW Car');
?>
and wants to know if the same person bought the same thing today and yesterday and use array_intersect($orders_today, $orders_yesterday) you'll get as result:
<?php
Array
(
[0] => Array
(
[0] => John Doe
[1] => PHP Book
)
[1] => Array
(
[0] => Jack Smith
[1] => Coke
)
)
?>
but we can get around that by serializing the inner arrays:
<?php
$orders_today[0] = serialize(array('John Doe', 'PHP Book'));
$orders_today[1] = serialize(array('Jack Smith', 'Coke'));
$orders_yesterday[0] = serialize(array('Miranda Jones', 'Digital Watch'));
$orders_yesterday[1] = serialize(array('John Doe', 'PHP Book'));
$orders_yesterday[2] = serialize(array('Z? da Silva', 'Uncle Tungsten'));
?>
so that array_map("unserialize", array_intersect($orders_today, $orders_yesterday)) will return:
<?php
Array
(
[0] => Array
(
[0] => John Doe
[1] => PHP Book
)
)
?>
showing us who bought the same thing today and yesterday =)
[]s
