json_encode not preserving order

Question

I have a multi dimensional array, in PHP:

Array
(
[1] => Array
    (
        [19] => Array
            (                    
                [type] =&g         


        

Answer 1

The problem is that in JavaScript only arrays are ordered, objects are not.

If you had something like:

array(
    array(
        'type' => 2
        'id' => 6
    ),
    array(
        'type' => 4
        'id' => 12
    ),
    array(
        'type' => 3
        'id' => 19
    )
)

Then in your JavaScript you'd have an array of objects, and that array would retain its order.

The reason it's out of order is because your array's index didn't start at 0, the keys were not in order and there were gaps in the keys. So, when encoded, PHP turned it into an object instead of an array.