Add Login and logout buttons to top menu bar

Question

I got this code to insert menu bar in the PRIMARY menubar, but I can not find a way to insert it into my secondary, or top menubar above the primary menu bar. Could anyone teach me how to do that?

add_filter( 'wp_nav_menu_items', 'add_loginout_link', 10, 2 );
function add_loginout_link( $items, $args ) {
    if (is_user_logged_in() && $args->theme_location == 'menu_top') {
      $items .= '<li><a href="'. wp_logout_url() .'">Log Out</a></li>';
    }
    elseif (!is_user_logged_in() && $args->theme_location == 'menu_top') {
      $items .= '<li><a href="'. site_url('wp-login.php') .'">Log In</a></li>';
    }
    return $items;
}

=============Additional Info============== I am using Custom Community Theme 1.4. Just in case it will be helpful, and I tried to use 'menu_top' as keyword rather than primary, but it does not work, it originally was primary!

==============MORE INFO==================== Ok, in request, I found more info, but as I tried, menu_top does not work, and seem these code already tell what is the name of the menu, is that right?

// This theme uses wp_nav_menu() in one location.
    register_nav_menus(array(
        'menu_top' => __('Header top menu', 'cc'),
        'primary' => __('Header bottom menu', 'cc'),
    ));

Answer 1

"PRIMARY" and "secondary" menu bar really don't mean anything when used out of context and without explanation. However, (guessing a lot) if your menus are constructed consistently you should be able to find the 'name' of the second menu and add a condition like (overly formatted for readability):

if (
  is_user_logged_in() 
  && (
    $args->theme_location == 'menu_top' 
    || $args->theme_location == 'other_menu_name'
  )
) { 
    $items .= '<li><a href="'. wp_logout_url() .'">Log Out</a></li>';

Same with the elseif.

Look for a call to wp_nav_menu in your theme files to find the 'name' of the second menu.