Question

This problem is a bit strange. Why is showed “Is not null”, if the value sent is null? Any reason for that?

Parametersapplication/x-www-form-urlencoded
lists_owned null
Source
lists_owned=null

<?php
$lists_owned = $_POST['lists_owned'];

var_dump($lists_owned); // string(4) "null"

if(!is_null($_POST['lists_owned'])) {
    echo "Is not null"; I see this echo
}
?>  

thanks

Answer 1

"null" is not null. If you want to check for "null" then you should be using equality.

if($_POST['lists_owned'] != 'null') {