我怎么能完全破坏会话。 如果会话不可用则重定向到登录页面

Question

Hello i am trying to destory session when i press signout button then it's logging out and redirecting to login page; but when click back in browser that page is loading with loign menu on top.

And i have wrote a code in everypage as if session not available redirect to login page.

Here is my logout code for session_destroy:

elseif(isset($_GET['type']) && $_GET['type']== "logout" )
{
    if (!isset($_SESSION['id'])) {
        header('location:index.php');
        } else {
        session_destroy();
        $_SESSION = array(); 
        header('location:index.php');
    }
}

here is the code what i have mentioned in all pages:

session_start();
include_once('includes/config.php');
if(!isset($_SESSION['id'])) {
    header('location:login.php');
}

So my question is completly logout if press back it should not load and has to redirect to login page.

Answer 1

<?php
session_start();
if($_SESSION['id']){
unset($_SESSION['id']); // destroys the specified session.

}

header('Location:index.php'); //redirect to preferred page after unset the session

?>