Transpose array with 3 levels while retaining middle level (associative key)

Question

I want to combine these arrays in a new array based on the same key number for creating tables. This is my code.

$arr3 = array();

print '<pre>';
print_r($bonus_table);
print '</pre>';

foreach($bonus_table as $key => $row) {
    $arr3 = array_merge($row['cells'],$arr3);
}

return $arr3;

And this is the output from my code. Basically this is the current structure of array:

Array
  (
            [0] => Array
                (
                    [cells] => Array
                        (
                            [0] => DEPOTS
                            [1] => PRICES
                        )

                )

            [1] => Array
                (
                    [cells] => Array
                        (
                            [0] => 50
                            [1] => 25
                        )

                )

            [2] => Array
                (
                    [cells] => Array
                        (
                            [0] => 100
                            [1] => 50
                        )

                )
)

But I want to convert the above output with the below structure. The desired array should look like this:

Array
        (
            [0] => Array
                (
                    [cells] => Array
                        (
                            [0] => DEPOTS
                            [1] => 50
                            [2] => 100
                        )

                )
            [1] => Array
                (
                    [cells] => Array
                        (
                            [0] => PRICES
                            [1] => 25
                            [2] => 50
                        )
                )
         )

_"I have these arrays list:"_ - that only shows us your data, but not what variable(s) this is actually contained in. Please provide a proper [mre] when asking this kind of question. — CBroe, Mar 29 '23 at 12:16
Sorry, I did some changes in my post. I hope to explained better now. — Epi94, Mar 29 '23 at 12:53

score 0 · Answer 1 · answered Mar 29 '23 at 13:23

Replacing your foreach loop with the below will produce the data you are after:

$arr3 = [
    [
        'cells' => ['Depots']
    ],
    [
        'cells' => ['Prices']
    ]
];

foreach ($bonus_table as $input) {
    if (is_numeric($input['cells'][0]) && is_numeric($input['cells'][1])) {
        $output_array[0]['cells'][] = $input['cells'][0];
        $output_array[1]['cells'][] = $input['cells'][1];
    }
}

Demo: https://onlinephp.io/c/06b36

Here we are looping through the input array ($bonus_table) and collecting data in an output array ($arr3).

score 0 · Answer 2 · answered Mar 29 '23 at 13:59

You simply could use array_column

<?php

$bonus_table = [];
$bonus_table[]['cells'] = ["DEPOTS", "PRICES"];
$bonus_table[]['cells'] = [50, 25];
$bonus_table[]['cells'] = [100, 50];

$formattedArray = [];

// The bonus_table first level could be useless
$cellsArray = array_column($bonus_table, 'cells');

foreach($cellsArray as $key => $row) {
    if (array_key_exists($key, $row)) {
        $formattedArray[]["cells"] = array_column($cellsArr, $key);
    }
}

outout

Array
(
    [0] => Array
        (
            [cells] => Array
                (
                    [0] => DEPOTS
                    [1] => 50
                    [2] => 100
                )

        )

    [1] => Array
        (
            [cells] => Array
                (
                    [0] => PRICES
                    [1] => 25
                    [2] => 50
                )

        )

)

score 0 · Answer 3 · answered Mar 30 '23 at 02:06

Because you have 3 levels in your array and the middle level uses cells as the key which needs to be retained, array transposition can be done swiftly without out any function calls by nesting a loop inside of another.

For the record, I don't see a lot of value in having the redundant cells level in your array structure.

Code: (Demo)

$result = [];
foreach ($array as ['cells' => $data]) {
    foreach ($data as $i => $v) {
        $result[$i]['cells'][] = $v;
    }
}
var_export($result);

Transpose array with 3 levels while retaining middle level (associative key)

3 Answers3