How to check if a user is logged-in in php?

Question

I\'m pretty new to php and I am trying to figure out how to use sessions to check and see if a user is logged into a website so that they would have authorization to access

Answer 1

Need on all pages before you check for current sessions

session_start();

Check if $_SESSION["loggedIn"] (is not) true - If not, redirect them to login page.

    if($_SESSION["loggedIn"] != true){
       echo 'not logged in';
       header("Location: login.php");
       exit;
    }