如何将此多维PHP数组作为JSON对象返回？

Question

I have this code in my model when the controller requests to get all the messages for a certain user:

public function get_messages($user_id) {
    $sql = "SELECT * 
            FROM messages 
            WHERE `to` = '$user_id'
            ORDER BY id DESC";

    $query = $this->db->query($sql);        
    foreach($query->result() as $row) {
        $messages[] = array(
            'id' => $row->id,
            'to' => $row->to,
            'from' => $row->from,
            'message' => $row->message,
            'star' => $row->star,               
            'timestamp' => $row->timestamp          
        );
    }
    return $messages;
}

Here's the code in my controller:

$result = $this->inbox_m->get_messages($user['id']);

How can I return the result as a JSON object using PHP's json_encode() function?

Normally I do something like this for simple returns:

json_encode(array('result' => true))

but all these arrays in arrays got me confused.

EDIT

Never mind guys, should have actually tried it before posting. This works just fine:

echo json_encode(array('result' => $result));

I will close the question in a day when my account allows me.

Answer 1

json_encode($messages); should be fine here. Call it and examine the output to see if it's what you want. But json_encode should handle nested arrays without breaking a sweat.

Answer 2

Closing the question by answering it myself. Like explained in the edit this works just fine:

echo json_encode(array('result' => $result));