Inconsistent return values in Laravel collections

I am working on a thread based messaging system.

I have a simple query to return all of the messages for a specific thread like that:

$t->messages->sortByDesc('updated_at')

While passing this to the return response()->json(), if it has one message the return value is an array. While if it has more than one messages the return value is an object of objects like that {0 => {messageattribs}, 1 => {messageattribs}}.

I would like to know why is this, and why it doesn't follow the array without the index keys patterns as in the first case.

via Chebli Mohamed