note 54417 deleted from function.array-flip by danbrown

Note Submitter: crescentfreshpot at yahoo dot com ---- Furthering benles note, if you don't want duplicate values to overwrite existing keys but need non-duplicate values to be assigned like array_flip, use: <?php function array_invert($arr) { $flipped = array(); foreach(array_keys($arr) as $key) { if(array_key_exists($arr[$key],$flipped)) { $flipped[$arr[$key]] = array_merge((array)$flipped[$arr[$key]], (array)$key); } else { $flipped[$arr[$key]] = $key; } } return $flipped; } $a = array( 'orange' => 'fruit', 'milk' => 'dairy', 'apple' => 'fruit', 'banana' => 'fruit' ); print_r(array_invert($a)); /* Output: Array ( [fruit] => Array ( [0] => orange [1] => apple [2] => banana ) [dairy] => milk ) */ ?>