note 111173 added to function.array-combine

You can create an array hashset from a flat array, storing both keys and values, with array_combine(). This works with duplicate values in the array too. <?php $flat_array = array( 'one', 'two', 'three', 'three', 'four', 'one' ); $set = array_combine($flat_array, $flat_array); var_dump($set); ?> This outputs the following: array(4) { ["one"]=> string(3) "one" ["two"]=> string(3) "two" ["three"]=> string(5) "three" ["four"]=> string(4) "four" } ---- Server IP: 192.41.42.26 Probable Submitter: 38.122.108.2 ---- Manual Page -- http://php.net/manual/en/function.array-combine.php Edit -- https://master.php.net/note/edit/111173 Del: integrated -- https://master.php.net/note/delete/111173/integrated Del: useless -- https://master.php.net/note/delete/111173/useless Del: bad code -- https://master.php.net/note/delete/111173/bad+code Del: spam -- https://master.php.net/note/delete/111173/spam Del: non-english -- https://master.php.net/note/delete/111173/non-english Del: in docs -- https://master.php.net/note/delete/111173/in+docs Del: other reasons-- https://master.php.net/note/delete/111173 Reject -- https://master.php.net/note/reject/111173 Search -- https://master.php.net/manage/user-notes.php