Question

I need some help with sorting a multidimensional array in php. I need the array to be grouped into months, and then sorted by month. Here’s my original array:

Array
(
    [0] => Array
        (
            [IdEvent] => 5
            [EventName] => Copy of Opening snow weekend
            [Year] => 2011
            [Month] => 08
        )

    [1] => Array
        (
            [IdEvent] => 7
            [EventName] => Copy of Copy of Opening snow weekend
            [Year] => 2011
            [Month] => 07
        )

    [2] => Array
        (
            [IdEvent] => 1
            [EventName] => Opening snow weekend
            [Year] => 2011
            [Month] => 05
        )

    [3] => Array
        (
            [IdEvent] => 6
            [EventName] => Copy of Opening snow weekend
            [Year] => 2011
            [Month] => 05
        )

)

And here’s what I’m hoping to get:

Array
(

    [0] => Array (

        [0] => Array
            (
                [IdEvent] => 1
                [EventName] => Opening snow weekend
                [Year] => 2011
                [Month] => 05
            )

        [1] => Array
            (
                [IdEvent] => 6
                [EventName] => Copy of Opening snow weekend
                [Year] => 2011
                [Month] => 05
            )

    )

    [1] => Array (

        [0] => Array
            (
                [IdEvent] => 7
                [EventName] => Copy of Copy of Opening snow weekend
                [Year] => 2011
                [Month] => 07
            )

    )

    [2] => Array (

        [0] => Array
            (
                [IdEvent] => 5
                [EventName] => Copy of Opening snow weekend
                [Year] => 2011
                [Month] => 08
            )
    )

)

Answer 1

I would use an easily sortable key for each month-container, then just use ksort

$months = array();
foreach ($input_array AS $arr) {
  $months[$arr['Month']][] = $arr;
}
ksort($months);

if you want, you can then use array_values to turn it into a standard integer-key array