搜索并替换数组php中的键的值

Question

I have array like this:

array(
    [0] => Array
    (
        [q_id] => 314
        [answer_type] => RI
        [answer] => 3438
        [user_id] => 
    )

[1] => Array
    (
        [q_id] => 286
        [answer_type] => NM
        [answer] => 5
        [user_id] => 
    )

[2] => Array
    (
        [q_id] => 207
        [answer_type] => SS
        [answer] => 1
        [user_id] => 1
    )
 )

Its expected to have same user_id for all questions that have value for user_id or empty. I want to replace empty user_ids with the existing user_id.

Any better ways to do it other than looping / array_walk?

Answer 1

Don't think so.

$arr = array_map(function ($val) use ($user_id) {
    if (empty($val['user_id'])) {
        $val['user_id'] = $user_id;
    }

    return $val;
}, $arr);

I am of course assuming you have PHP 5.3+