Drop down menus with wp_nav_menu or wp_page_menu

Question

i have some doubts on what i am actually supposed to use to create drop down menus.By just looking at theme twenty ten,i have ,

<div id="access" role="navigation">
              <?php /*  Allow screen readers / text browsers to skip the navigation menu and get right to the good stuff */ ?>
                <div class="skip-link screen-reader-text"><a href="#content" title="<?php esc_attr_e( 'Skip to content', 'twentyten' ); ?>"><?php _e( 'Skip to content', 'twentyten' ); ?></a></div>
                <?php /* Our navigation menu.  If one isn't filled out, wp_nav_menu falls back to wp_page_menu.  The menu assiged to the primary position is the one used.  If none is assigned, the menu with the lowest ID is used.  */ ?>
                <?php wp_nav_menu( array( 'container_class' => 'menu-header', 'theme_location' => 'primary' ) ); ?>
            </div>

In the comments its written "If one isn't filled out, wp_nav_menu falls back to wp_page_menu..."

When writing the css for the drop down menus,does it mean i have to write one for the menus created in the apprerance->menus wp admin backend and one for when the navigation from the wp admin backend is not available.

Answer 1

"If one isn't filled out, wp_nav_menu falls back to wp_page_menu..."

Means, if you do not create a nav menu from the Menus section in the back end, then as a fall back, wp_page_menu will be used (Check the fallback parameter for wp_nav_menu, it is set to wp_page_menu by default). It completely depends on how you implement it in your theme. You can use wp_list_pages instead of wp_page_menu as your fallback. The CSS you apply will be applied relative to the container class menu-header. You can use whatever class you want to wrap the menu.