Check if a session exists and a variable has been set #php

is-new-session.php

<?
function isNewSession() {
  if(session_id() == '' || !isset($_SESSION) || session_status() === PHP_SESSION_NONE) {
    // session isn't started
    session_set_cookie_params(3600,"/"); // 1 hour
    session_start();
  }

  if (!isset($_SESSION['new_session'])) {
    $_SESSION['new_session'] = true;
  }
  else {
    $_SESSION['new_session'] = false;
  }

  return $_SESSION['new_session'];
}