array_push() expects parameter 1 to be array, null given

Question

I have the following php code:

<?php

class Session {

    public function __construct() {
        if (!session_id()) {
            session_start();
        }
        if (!is_array($_SESSION['messages'])) {
            $_SESSION['messages'] = [];
        }
        echo is_array($_SESSION['messages']);
    }

    public function AddMessage($msg="") {
        array_push($_SESSION['messages'], $msg);
    }

    public function GetMessages() {
        $messages = $_SESSION['messages'];
        unset($_SESSION['messages']);
        return $messages;
    }

}

$session = new Session();

?>

And the output of $session->AddMessage('message') is:

1 
Warning: array_push() expects parameter 1 to be array, null given in ...\Session.php on line 16

so is_array clearly says that $_SESSION['messages'] IS an array. What am I missing?

I am not able to reproduce your error, this is usually caused by missing information in the question. Are you calling the $session->AddMessage('message') immediately after $session = new Session()? — Scott
– Scott, Commented Jan 21, 2016 at 18:37
Did you happen to call GetMessages() before AddMessage()? — AbraCadaver
– AbraCadaver, Commented Jan 21, 2016 at 18:38
Note: OP has edited the stackoverflow.com/revisions/34931400/1 — Thamilhan
– Thamilhan, Commented Jan 21, 2016 at 18:40
@user3210615 No problem, actually you shouldn't update answer in your question. So that any future visitors might find the right answer from the answer section. not in the question itself — Thamilhan
– Thamilhan, Commented Jan 21, 2016 at 18:59

Community · Accepted Answer · 2017-05-23 12:07:27Z

1

session_id is a function, so it should be:

    if (!session_id()) { //Not just session_id
        session_start();
    }

If you would have turned on error reporting it might have thrown:

Notice: Use of undefined constant session_id - assumed 'session_id'

Note: OP has edited the original question

edited May 23, 2017 at 12:07

CommunityBot

11 silver badge

answered Jan 21, 2016 at 18:30

Thamilhan

13.3k5 gold badges40 silver badges60 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

array_push() expects parameter 1 to be array, null given

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related