Online PHP editor | refs for jKuRb

<?php $afr = function(&$v) use (&$afr) { if (is_array($v)) { foreach($v as $key=>$val) { if (empty($val)) unset($v[$key]); if (is_array($val)) $v[$key] = $afr($val); } } return $v.'modified'; }; $a = ['',['',['a', 'b'],'c'],'d']; $b = $a; var_dump($afr($b)); ?><hr><?php var_dump($a);