Online PHP editor | refs for J1NeJ

<?php /** * Flatten a multi-dimensional array to a single-level array, * sorting the entries in order to depth first. * * @param array $carry Optional Array to initialize * @param mixed $subject Array or value that has data in potential multi-dimensions. * * @return array */ function array_flatten(?array $carry = [], $subject): array { return array_reduce((array) $subject, function(array $carry, $item) { return is_array($item) ? array_flatten($carry, $item) : array_merge($carry, (array) $item); }, (array) $carry); } print_r(array_flatten(null, array( array('A', array('B', array('CC','CCCC','CCCCCC'), array('DDD','EFG','HIJ','LMNOP') ) ), array('2'), 'b', array(array(),array(),array()), ))); $array = array(1,2,[3,4],5,'six',array(array('78',9)),10); print_r(array_reduce($array, "array_flatten"));