gistfile1.php

if (is_user_logged_in()){
  wp_nav_menu( array(
    'menu'            => 'Logged In Menu',
    'container_class' => 'logged-in-menu',
    'theme_location'  => 'logged-in'
  ));
} else {
  wp_nav_menu( array(
    'menu'            => 'Visitor Menu',
    'container_class' => 'visitor-menu',
    'theme_location'  => 'visitor'
  ));
};