3v4l.org

run code in 300+ PHP versions simultaneously
<?php // Everything you enter here will be executed by our servers. Try it! $data = array( array('a', 'b', 'c', 'd', 'e'), array('f', 'g', 'h', 'i', 'j'), array('k', 'l', 'm', 'n', 'o'), array('p', 'q', 'r') ); $width = count($data[0]); // 5 $height = count($data); // 4 $total = $width * $height; // 20 $new_data = array(); for($i = 0; $i < $total; $i++) { $old_x = floor($i / $width); // integer division $old_y = $i % $width; // modulo $new_x = $i % $height; // modulo $new_y = floor($i / $height); // integer division if (!isset($new_data[$new_x])) { $new_data[$new_x] = array(); } if (isset($data[$old_x][$old_y])) { $new_data[$new_x][$new_y] = $data[$old_x][$old_y]; } } print_r($new_data);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.30, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Array ( [0] => Array ( [0] => a [1] => e [2] => i [3] => m [4] => q ) [1] => Array ( [0] => b [1] => f [2] => j [3] => n [4] => r ) [2] => Array ( [0] => c [1] => g [2] => k [3] => o ) [3] => Array ( [0] => d [1] => h [2] => l [3] => p ) )

preferences:
300.07 ms | 407 KiB | 386 Q