3v4l.org

run code in 300+ PHP versions simultaneously
<?php $in = array(); for($i = 1; $i <=5; $i++) { $in[] ='category_id'['sss'] ; } $res = array();// Array where we will write result $t = &$res; // Link to first level foreach ($in as $k) { // Walk through source array if (empty($t[$k])) { // Check if current level has required key $t[$k] = []; // If does not, create empty array there $t = &$t[$k]; // And link to it now. So each time it is link to deepest level. } } unset($t); // Drop link to last (most deep) level var_dump($res);
Output for 8.0.0 - 8.0.3
Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /in/ACvWc:6 Stack trace: #0 {main} thrown in /in/ACvWc on line 6
Process exited with code 255.
Output for 7.3.0 - 7.3.28, 7.4.0 - 7.4.16
Warning: Illegal string offset 'sss' in /in/ACvWc on line 6 Warning: Illegal string offset 'sss' in /in/ACvWc on line 6 Warning: Illegal string offset 'sss' in /in/ACvWc on line 6 Warning: Illegal string offset 'sss' in /in/ACvWc on line 6 Warning: Illegal string offset 'sss' in /in/ACvWc on line 6 array(1) { ["c"]=> array(1) { ["c"]=> array(1) { ["c"]=> array(1) { ["c"]=> array(1) { ["c"]=> array(0) { } } } } } }