Using ksort to sort by year and month with php?

Question

This is my php function which returns an array of year, month and associative values

function byCalendarMonth($tmpArray) {
    $output = [];
    foreach ($tmpArray as $value) {
        $year = date('Y', strtotime($value['date']));
        $month = date('M', strtotime($value['date']));

        if (empty($output[$year][$month]))
            $output[$year][$month] = ['Indoor' => 0, 'Gym class' => 0];
        // Check for incident intensity
        $output[$year][$month][$value['category']] += $value['score'];
    }

    ksort($output);
    ksort($output[$year][$month]);
    return $output;
}

and the output looks like

Array
(
    [2016] => Array
        (
            [Dec] => Array
                (
                    [Indoor] => 39
                    [Gym class] => 34
                )

            [Nov] => Array
                (
                    [Indoor] => 56
                    [Gym class] => 41
                )

            [Oct] => Array
                (
                    [Indoor] => 82
                    [Gym class] => 66
                )

            [Sep] => Array
                (
                    [Indoor] => 97
                    [Gym class] => 89
                )

            [Aug] => Array
                (
                    [Indoor] => 74
                    [Gym class] => 78
                )

            [Jul] => Array
                (
                    [Indoor] => 0
                    [Gym class] => 3
                )

            [Jun] => Array
                (
                    [Indoor] => 74
                    [Gym class] => 98
                )

            [May] => Array
                (
                    [Indoor] => 102
                    [Gym class] => 58
                )

            [Apr] => Array
                (
                    [Gym class] => 49
                    [Indoor] => 106
                )

        )

    [2017] => Array
        (

            [Mar] => Array
                (
                    [Indoor] => 67
                    [Gym class] => 53
                )

            [Feb] => Array
                (
                    [Indoor] => 81
                    [Gym class] => 47
                )

            [Jan] => Array
                (
                    [Indoor] => 84
                    [Gym class] => 49
                )

        )

)

But I just need the months to ASC like jan, feb, mar etc??

Answer 1

Replace

ksort($output[$year][$month]);

with

$month_names = ['Jan','Feb'...];
foreach($output as $year) {
   uksort($year, 
          function($a, $b) use($month_names) {
             return array_search($a, $month_names, true) - array_search($b, $month_names, true);
          }); 
}

uksort function

array_search function

Answer 2

There are few solutions.

First. If you know exactly range of years, you can generate empty array with years and months. In this, you will never miss any month. Something like that...

$years = [];
for ($year = 2015; $year <= 2017; $year++ ) {
  $years[$year] = ['Jan' => [], 'Feb' => [], ...];
}

Second. You can replace ksort($output[$year][$month]) to

$listOfOrderedMonth = ['Jan', 'Feb', ...];


$result = [];
foreach ($output as $year => $months) {
    foreach ($listOfOrderedMonth as $orderedMonth) {
        $result[$year][$orderedMonth] = $months[$orderedMonth];
    }
}