Question

I have a result set from a DB that returns the following array…. how do I implode this into a comma delimited string?

Array
(
    [0] => Array
        (
            [user_id] => 2
        )

    [1] => Array
        (
            [user_id] => 5
        )

    [2] => Array
        (
            [user_id] => 11
        )
)

Answer 1

$t = array_map(function (array $a) { return $a["user_id"]; }, $original_array);
$result = implode(",", $t);

(PHP 5.3+, the closure must be turned into a regular function for earlier versions)