Populate 2D array from each value in an array of arrays

Question

I have a 2D array and I want to generate a formatted array. Actually I want to genetate multiple rows at a time by restructuring the input array.

My 2D array:

$occupied_ids = [
    [8457, 6584],
    [9874, 4586],
];

Expected output:

array (
  0 => 
  array (
    'occupied_id' => 8457,
    'feed' => 2,
    'status' => 1,
    'status_date' => '2022-09-13',
  ),
  1 => 
  array (
    'occupied_id' => 6584,
    'feed' => 2,
    'status' => 1,
    'status_date' => '2022-09-13',
  ),
  2 => 
  array (
    'occupied_id' => 9874,
    'feed' => 2,
    'status' => 1,
    'status_date' => '2022-09-13',
  ),
  3 => 
  array (
    'occupied_id' => 4586,
    'feed' => 2,
    'status' => 1,
    'status_date' => '2022-09-13',
  ),
)

My working code:

foreach($occupied_ids as $ele){
    $attributes = array_map(function($v){
        $feed = isset($_GET['feed']) ? $_GET['feed'] : 2;
        $status = 1;
        return [
            'occupied_id'   =>  $v,
            'feed'          =>  $feed,
            'status'        =>  $status,
            'status_date'   =>  date('Y-m-d'),
       ];
    }, $ele);

    /*Call function to multi-insert*/
    //multi_insert($attributes);
}

But I'm looking for something a way without the outer loop.

Why do you not want to loop? – gen_Eric Oct 15 '15 at 15:33 — gen_Eric, Oct 15 '15 at 15:33
Bcz my array size is very long. – Deev Junior Oct 15 '15 at 15:35 — Deev Junior, Oct 15 '15 at 15:35
Isn't that an even stronger reason to loop? – Jon Tan Oct 15 '15 at 15:38 — Jon Tan, Oct 15 '15 at 15:38

score 1 · Accepted Answer · answered Oct 15 '15 at 15:58

Not sure how much better it is but I took a stab at it. Off to lunch but I'll revisit in a bit to see what can be optimized:

$occupied_ids = call_user_func_array('array_merge', $occupied_ids);

$temp = [   'feed'          =>  isset($_GET['feed']) ? $_GET['feed'] : 2,
            'status'        =>  1,
            'status_date'   =>  date('Y-m-d'),
       ];

$attributes = array_map(function($v) use($temp) {
                            $r = $temp;
                            $r['occupied_id'] = $v;
                            return $r;
                        },
                        $occupied_ids);

score 1 · Answer 2 · answered Oct 15 '15 at 16:05

Use array_reduce to flatten the first level of the array

$occupied_ids = [
    [8457, 6584],
    [9874, 4586],
];

function format_elem($v)
{
        $feed = isset($_GET['feed']) ? $_GET['feed'] : 2;
        return [
            'occupied_id'   =>  $v,
            'feed'          =>  $feed,
            'status'        =>  1,
            'status_date'   =>  date('Y-m-d'),
       ];
}
$ids=array_reduce($occupied_ids,'array_merge',[]);
$attributes =array_map(format_elem,$ids);

score 0 · Answer 3 · answered Sep 13 '22 at 08:19

By pre-flattening your data (by spreading the rows inside of an array_merge() call), you can call array_map() instead of array_reduce() because now the input will have the same number of rows as the desired output.

Code: (Demo)

var_export(
    array_map(
        fn($v) => [
            'occupied_id'   =>  $v,
            'feed'          =>  $_GET['feed'] ?? 2,
            'status'        =>  1,
            'status_date'   =>  date('Y-m-d'),
        ],
        array_merge(...$occupied_ids)
    )
);

Populate 2D array from each value in an array of arrays

3 Answers3