How can I convert 3-D multidimentional array to 1-D array as below where I want to insert last array's values into that particular array's keys?

Question

My Array is as below.

Array
(
    [data] => Array
        (
            [28] => Array
                (
                    [0] => 201
                    [1] => 202
                )
            [29] => Array
                (
                    [0] => 301
                    [1] => 302
                )
            [30] => Array
                (
                    [0] => 401
                    [1] => 402
                )
        )
)

I want to convert this array as below.

myarray = Array
    (
        [0] => Array
            (
                [data1] => 28
                [data2] => Array
                    (
                        [0] => 201
                        [1] => 202
                    )
            )
        [1] => Array
            (
                [data1] => 29
                [data2] => Array
                    (
                        [0] => 301
                        [1] => 302
                    )
            )
        [2] => Array
            (
                [data1] => 30
                [data2] => Array
                    (
                        [0] => 401
                        [1] => 402
                    )
            )
    )

After converting the array as above, I am about to insert data1 and data2 values into database. Where I will loop like

for($i=0;$i<count($myarray);$i++)
{
  $year = $myarray[$i]['data1'];
  for($j=0;$j<count($myarray[$i][data2]);$j++)
  {
    insert($year,$myarray[$i][data2][$j]);
  }
}

How can I do this? Please help me. Is this proper method in for loop where insert data into nested for loop. If our data array in too big like 10000 array counts for ($i) and 1000 counts for ($j), will it create problem for the insert function?

Any other proper conversion of array is also good for me. I just want to insert values like 201,202 with 28 and 301,302 with 29 into database.

Thank you.

Answer 1

Do you really need to have the intermediate array to then just insert the data?

It would be easier to follow the idea of using a foreach() to directly insert the data from the original array...

$myarray = [ "data" => [ 28 =>[201,202], 29 => [301,302]]];

foreach ( $myarray["data"] as $year => $data )  {
    foreach ( $data as $value2 ){
        insert($year,$value2);
    }
}

Answer 2

This will do the trick:

<?php

$arr = [
    'data' => [
        28 => [201,202],
        29 => [301,302],
        30 => [401,402],
    ]
];

$return = [];
foreach ($arr['data'] as $key => $value) {
    $return[] = ['data1' => $key, 'data2' => $value];
}

var_dump($return);