PHP – Add a new element into each multidimensional array

I have an array that looks like this:

Array
(
    [0] => stdClass Object
        (
            [quiz_id] => 1033
            [quiz_venue] => 6
            [quiz_host] => 46
            [quiz_golden_question] => 100
            [quiz_golden_question_outcome] => 0
            [quiz_running] => 1
            [quiz_status] => 100
            [quiz_trainee] => 0
        )

    [1] => stdClass Object
        (
            [quiz_id] => 985
            [quiz_venue] => 57
            [quiz_host] => 21
            [quiz_golden_question] => 0
            [quiz_golden_question_outcome] => 0
            [quiz_running] => 1
            [quiz_status] => 310
            [quiz_trainee] => 0
        )

I want to go through each array, and insert a new value (quiz_venue_name), this is what I have;

$quizzes = $wpdb->get_results( $prepared );

        foreach ($quizzes as $quiz => $item) { 
            $venuetitle = get_the_title($item->quiz_venue);
            $quizzes['quiz_venue_name'] = $venuetitle;
        }

        return $quizzes;

However, all it does is add the new values to the very end of the multidimensional array as new arrays – rather than adding them into each!

I feel like I’m doing something obvious wrong, so any help is much appreciated!

The end result I need would be;

Array
(
    [0] => stdClass Object
        (
            [quiz_id] => 1033
            [quiz_venue] => 6
            [quiz_host] => 46
            [quiz_golden_question] => 100
            [quiz_golden_question_outcome] => 0
            [quiz_running] => 1
            [quiz_status] => 100
            [quiz_trainee] => 0
[quiz_venue_name] => NEW VALUE
        )

    [1] => stdClass Object
        (
            [quiz_id] => 985
            [quiz_venue] => 57
            [quiz_host] => 21
            [quiz_golden_question] => 0
            [quiz_golden_question_outcome] => 0
            [quiz_running] => 1
            [quiz_status] => 310
            [quiz_trainee] => 0
[quiz_venue_name] => NEW VALUE
        )

>Solution :

Your $quizzes variable is an array of objects (Instance of stdClass), so you should use it attribute to set value in each iteration ($item->quiz_venue_name instead of $quizzes['quiz_venue_name']):

...
foreach ($quizzes as $quiz => $item) { 
    $venuetitle = get_the_title($item->quiz_venue);
    $item->quiz_venue_name = $venuetitle;
}
...

In fact the $quizzes['quiz_venue_name']=... code will be set a value for index quiz_venue_name in root of $quizzes array.