php - php sort multidimensional array by key

Question

I have array like this:

    $arr = [];

    $arr['cat1']=[
        'attributes'=>[
            [
                'attributeName'=>'name1',
                'attrSortOrder'=>'1'
            ],
            [
                'attributeName'=>'name2',
                'attrSortOrder'=>'5'
            ],
            [
                'attributeName'=>'name3',
                'attrSortOrder'=>'2'
            ],
        ],
        'category_id'=>10
    ];
    $arr['cat2']=[
        'attributes'=>[
            [
                'attributeName'=>'name4',
                'attrSortOrder'=>'5'
            ],
            [
                'attributeName'=>'name5',
                'attrSortOrder'=>'7'
            ],
            [
                'attributeName'=>'name6',
                'attrSortOrder'=>'2'
            ],
        ],
        'category_id'=>12
    ];

I need for each $arr element sort 'attributes' by attrSortOrder column. I tried it:

  function array_sort_by_column(&$arr, $col, $dir = SORT_ASC) {
        $sort_col = array();
        foreach ($arr as $key=> $row) {
            $sort_col[$key] = strtolower($row[$col]);
        }

        array_multisort($sort_col, $dir, $arr);
    }

          array_sort_by_column($arr,'attrSortOrder');

But it did not help me. How can solve this? How can i sort my array correctly? Thanks.

标签： phparrayssorting

Answer 1

Change your function to

function array_sort_by_column(&$arr, $col, $dir = SORT_DESC) {
  foreach($arr as &$v){//pass by reference each sub-array
    array_multisort(array_column($v['attributes'], 'attrSortOrder'), $dir, $v['attributes']);
  }
}
array_sort_by_column($arr,'attrSortOrder');

You can change second argument SORT_DESC OR SORT_ASC

Working example :- https://3v4l.org/pQ0Eu