merging a multi-dimensional array into another multi-dimensional array

Question

this relates to my previous post. how to create a collection of multi dimensional arrays and not overwrite origional values when new ones are pushed

i am thinking my problem has to do with how i am creating the array. what i'm trying to do is make an array that looks like this

Array
(
    [10] => Array
        (
           [0] => 29
           [1] => 36
        )

)

into something like this

    Array
    (
        [10] => Array
            (
               [0] => 29
               [1] => 36
            )


 [20] => Array
            (
               [0] => 29
               [1] => 36
            )


 [25] => Array
            (
               [0] => 29
               [1] => 36
            )

    )

the 10, 20, and 25 is the product id where the numbers within those are the selections that were selected on that page (in the link i gave above). so each product would have its own collection selected.

when i use array_push instead of doing what i want it to do the first collection of array as in the first example keep reseting. so if i do my selections on say flyers and add to cart then i go to business cards and do my selections and add to cart the array resets and it becomes like the first example. whatever i try i cant get it to merge below a collection like the second example that i have. i have tried array_merge(),array_push but those dont really work.

Answer 1

Solution:-

If you want to append array elements from the second array to the first array while not overwriting the elements from the first array and not re-indexing, use the + array union operator:

$a = array(10 => array(25,26));
$b = array(22 => array(45,66));
$c = $a + $b;
print_r($c);

Output:-

Array
(
    [10] => Array
        (
            [0] => 25
            [1] => 26
        )

    [22] => Array
        (
            [0] => 45
            [1] => 66
        )
)

Hope this helps.