Fatal error: Cannot redeclare class (PHP)

Question

I'm having big problems with this fatal error. I have 5 files and every of them contains one class (Nationality.php, Team.php, BoughtTickets.php, Users.php, Tickets.php) and two of them require other classes.

So here is index.php

<?php

require 'header.html';
require 'pages/first.html';
require 'class/db.php';

$c=DB::connect();

require 'pages/footer.html';
?>

---

Users.php

require 'Nationality.php';
require 'Team.php';
require 'BoughtTickets.php';

class Users{
    public $Email;
    public $Name;
    ...

---

BoughtTickets.php

require 'Tickets.php';

class BoughtTicket{

    public $IDTicket;
    public $Date;
    ...

Eveytime I want to login, it gives me fatal error. If I remove line require 'BoughtTickets.php'; from class Users, it works, but it won't display table in one file which requires class BoughtTickets.php. Do you have any idea what to do to solve the problem?

Thank you

Answer 1

Use require_once instead of require

Answer 2

You may come across this error if you have something like

class C
{
}

class B extends A
{
}

class A
{
}

Answer 3

Try with include_once instead of require.