Online PHP editor | refs for AbD92

<?php $arrays = [ [ 77 => ['Bold Condensed', 'Bold Condensed 2', 'Bold Condensed 3'], ], [ 77 => ['Bold Condensed'], 136 => ['Regular'], ], [ 77 => ['Bold Condensed (1, 2, 3)'], 168 => ['Regular', 'Bold'], ] ]; $result = []; foreach ($arrays as $set) { foreach ($set as $id => $row) { foreach ($row as $value) { if (!isset($lookup[$id][$value])) { $lookup[$id][$value] = $value; $result[$id][] = $value; } } } } var_export($result);