3v4l.org

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<?php $array = array ( 1, array (1, 2, array ( 1, 2 ) ), array (1, 2, 3), 2, array( 1, array ( 1, array (1, 2) ) ) ); function findActives($array, $path_child=null){ foreach ($array as $key => $unknown ) { $path_child[] = $array[$key]; /* if (in_array('2') { $path_child = array($key, "active"); } */ if (is_array($unknown)) { findActives($unknown, $path_child); } } return ($path_child); } // findActives($array); function array_flatten($array) { $return = array(); foreach ($array as $key => $value) { if (is_array($value)){ $return = array_merge($return, array_flatten($value));} else {$return[$key] = $value;} } return $return; } $path_child = array_flatten($array); print_r($path_child);
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 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
Array ( [0] => 1 [1] => 1 [2] => 2 [3] => 2 [4] => 2 [5] => 1 [6] => 2 [7] => 3 [8] => 1 [9] => 1 [10] => 1 [11] => 2 )

preferences:
324.49 ms | 406 KiB | 456 Q