How do I solve “Parameter must be an array or an object that implements Countable?” [duplicate]

Answer 1

How about this way with $result->num_rows?

if(isset($_GET['edit'])){
    $id = $_GET['edit'];
    $update = true;
    $result = $mysqli->query("SELECT * FROM isalonusers WHERE user_id=$id") or die($mysqli->error);
    if(isset($result->num_rows) && $result->num_rows > 0){
        $row = $result->fetch_array(MYSQLI_ASSOC);
        $username = $row['username'];
        $password = $row['password'];
    }
  }

See ref.: http://php.net/manual/en/mysqli.query.php