Sort a multidimensional array in PHP

Question

I have this multidimensional array, called $rent :

Array
(
    [product2] => Array
        (
            [dates] => Array
                (
                    [2013-07-25] => 2
                    [2013-07-23] => 1
                    [2013-07-21] => 3
                )

        )

    [product3] => Array
        (
            [dates] => Array
                (
                    [2013-07-24] => 5
                    [2013-07-22] => 4
                    [2013-07-20] => 3
                )

        )

    [product1] => Array
        (
            [dates] => Array
                (
                    [2013-07-29] => 1
                    [2013-07-28] => 2
                    [2013-07-27] => 2
                )

        )

)

I'd like to do a double sort:

1. First, by productX ascending
2. Then, for each product, by date of rent ascending

So that the resulting array would be:

Array
(
    [product1] => Array
        (
            [dates] => Array
                (
                    [2013-07-27] => 2
                    [2013-07-28] => 2
                    [2013-07-29] => 1
                )

        )

    [product2] => Array
        (
            [dates] => Array
                (
                    [2013-07-21] => 3
                    [2013-07-23] => 1
                    [2013-07-25] => 2
                )

        )

    [product3] => Array
        (
            [dates] => Array
                (
                    [2013-07-20] => 3
                    [2013-07-22] => 4
                    [2013-07-24] => 5
                )

        )

)

How can I reach this? Many thanks in advance

Answer 1

try this:

ksort($rent);
foreach($rent as &$item) {
    ksort($item['dates']);
}

Answer 2

You can simply ksort the products, then iterate through them and use the same for the dates key.

ksort($products);

foreach($products as &$product)
    ksort($product['dates']);

Where $products is the array you showed us. Note that you need to pass the value in the foreach loop as a reference (using the & operator) otherwise the changes won't be updated in the original array.

Answer 3

for my understanding of your problem; Nadh solution is almost there. but i believe you want ksort()

this is my corrections to Nadh answer

ksort($rent);

foreach($rent as $product => $dates) {
    ksort($rent[$product]['dates']);
}

print_r($rent);