Looping over a multidimensional array

[makamo66]

<?php
$_SESSION["cart_item"] = array(
'cart_item' => array(
'id' => $id,
'product_name' => $product_name
));
}
$cart_items = $_SESSION["cart_item"];

foreach ($cart_items as $cart_item) {
echo $cart_item["id"] . $cart_item["product_name"];
}
?>

I have tried several variations of the foreach loop like the one above and I mostly get the error message: Notice: Array to string conversion. When I use:
var_dump($cart_items);

I get the following output:

array(1) { ["cart_item"]=> array(2) { ["id"]=> array(2) { [0]=> string(1) "2" [1]=> string(1) "3" } ["product_name"]=> array(2) { [0]=> string(19) "Adult Female Bike" [1]=> string(18) "Kids Unisex Bike" } } }

[makamo66]

The solution can't include nested foreach loops because I will be adding 3 more inner arrays to the multidimensional array and when I do this with nested foreach loops, I need 6 of them.

[makamo66]

I retract my original question because I don't need to make my multidimensional-array any larger after all. Please ignore my post.