当我调用索引0但是当我打印整个数组PHP时，数组为空

So when i use this:

print_r($events->getLocation($event['event_name']));

It returns:

Array
(
    [0] => Array
        (
            [location] => Düsseldorf, Germany
        )
)

But when i use this:

print_r($events->getLocation($event['event_name'][0]));

It returns this:

Array
(
)

$event is an array from a foreach and $events is my class.

print_r($events->getLocation($event['event_name'])[0]);