Transpose a PHP multidimensional array with predefined keys

Question

I have a multidimensional array with 3 keys ("length", "width" and "height). Each key is associated with an array of values:

$data = [
    "length" => ["12", "44"],
    "width" => ["22", "45"],
    "height" => ["22", "34"]
];

How can I transpose the columns of each key into rows of 3 columns as follows:

$rows = [
    ["length" => "12", "width" => "22", "height" => "22"],
    ["length" => "44", "width" => "45", "height" => "34"]
]; 

Answer 1

The following function will do the job:

function transpose($data)
{
    $result = [];
    $keys = array_keys($data);
    for ($row = 0,  $rows = count(reset($data)); $row < $rows; $row++) {
        foreach ($keys as $key) {
            $result[$row][$key] = $data[$key][$row];
        }
    } 

    return $result;
}

Notice that the function is a general solution it doesn’t depend on the name of the keys nor on the number of entries of each key.