Transposing Multidimensional Arrays in PHP

Transpose rows and columns in a 2D array

This should give you what you need.

function transpose($array_one) {
    $array_two = [];
    foreach ($array_one as $key => $item) {
        foreach ($item as $subkey => $subitem) {
            $array_two[$subkey][$key] = $subitem;
        }
    }
    return $array_two;
}

Then just pipe your existing array into the function and render the resulting array.

Transpose a PHP multidimensional array with predefined keys

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.

How to transpose array elements?

Here's an approach:

$categories = array(
    'item_name' => array('I-Phone', 'samsung', 'nokia','htc'),
    'item_price' => array('30.00', '20', '10', '15')
);

$out = array();
foreach($categories as $key => $a){
    foreach($a as $k => $v){
        $out[$k][$key] = $v;
    }
}
echo '<pre>';
print_r($out);
echo '</pre>';

Transpose multidimensional array and join values with commas

Just extract each column incrementally and join it. This only works with sub-arrays as shown with 0 based sequential indexes:

$i = 0;
while($new = array_column($array, $i)) {
    $result[] = implode(', ', $new);
    $i++;
}

For other non-0 based, non-sequential, non-integer, just re-index the sub-arrays before extracting and joining:

$array = array_map(function($v) { return array_values($v); }, $array);

Is there better way to transpose a PHP 2D array?

Nope. That's the most elegant.

Transpose a multidimensional associative array into a multidimensional indexed array sorted against and an external associative key

Probably the simplest thing is to just iterate over all the values, sorting them into a car indexed array. You can then use ksort to sort the data:

$output = array();
foreach ($array as $key => $a) {
    foreach ($a as $car => $v) {
        $output[$car][$key] = $v;
    }
}
ksort($output);
$array_cars = array_keys($output);
$compiled_data = array_values($output);
var_export($array_cars);
var_export($compiled_data);

Output:

array (
  0 => 'BMW',
  1 => 'Ford',
  2 => 'Land Rover',
  3 => 'Nissan',
  4 => 'Saab',
  5 => 'Volvo',
)
array (
  0 => 
  array (
    0 => 13,
    2 => 9,
  ),
  1 => 
  array (
    2 => 17,
  ),
  2 => 
  array (
    0 => 11,
    2 => 22,
  ),
  3 => 
  array (
    1 => 10,
    2 => 2,
  ),
  4 => 
  array (
    0 => 5,
    1 => 4,
  ),
  5 => 
  array (
    0 => 22,
  ),
)

Demo on 3v4l.org

Create a multidimensional array based on number of values

You just need to loop over the input array and build the new array

$new = [];
foreach ($in as $key=>$arr) {
    $new[0][$key] = $arr[0];
    $new[1][$key] = $arr[1];
}