How to convert an array of arrays or objects to an associative array?

I had the exact same problem some days ago. It is not possible using array_map, but array_reduce does the trick.

$arr = array('a','b','c','d');$assoc_arr = array_reduce($arr, function ($result, $item) {    $result[$item] = (($item == 'a') || ($item == 'c')) ? 'yes' : 'no';    return $result;}, array());var_dump($assoc_arr);

result:

array(4) { ["a"]=> string(3) "yes" ["b"]=> string(2) "no" ["c"]=> string(3) "yes" ["d"]=> string(2) "no" }

As far as I know, it is completely impossible in one expression, so you may as well use a foreach loop, à la

$new_hash = array();foreach($original_array as $item) {    $new_hash[$item] = 'something';}

If you need it in one expression, go ahead and make a function:

function array_map_keys($callback, $array) {    $result = array();    foreach($array as $item) {        $r = $callback($item);        $result[$r[0]] = $r[1];    }    return $result;}

This is a clarification on my comment in the accepted method. Hopefully easier to read. This is from a WordPress class, thus the $wpdb reference to write data:

class SLPlus_Locations {    private $dbFields = array('name','address','city');    public function MakePersistent() {        global $wpdb;        $dataArray = array_reduce($this->dbFields,array($this,'mapPropertyToField'));        $wpdb->insert('wp_store_locator',$dataArray);    }    private function mapPropertyToField($result,$property) {        $result[$property] = $this->$property;        return $result;    }}

Obviously there is a bit more to the complete solution, but the parts relevant to array_reduce() are present. Easier to read and more elegant than a foreach or forcing the issue through array_map() plus a custom insert statement.

Nice!