Displays a navigation menu create din the appearance–Menus panel.

if not given a theme_location parameter, the function displays

the menu matching ID,slug,or name given by the menu parameter,if that menu has atleast 1 item,

otherwise, output of the function given by the fallback_cb parameter(wp_page_menu(),by default); otherwise nothing.

<php wp_nav_menu$args);?>

$theme_location
(string) (optional) The location in the theme to be used–must be registered with register_nav_menu() in order to be selectable by the user

$menu
(string) (optional) The menu that is desired; accepts (matching in order) id, slug, name.

Targeting all page as Menu

<div class="access">
<?php wp_nav_menu(); ?>
</div>

Targeting a specific Single Menu

<?php wp_nav_menu( array('menu' => 'Project Nav' )); ?>

Targeting multiple menu location wise in this case menu must registered.

wp_nav_menu( array( 'theme_location' => 'header' ) ); ?>
wp_nav_menu( array( 'theme_location' => 'footer' ) ); ?>

register_sidebar()

Builds the definition for a single sidebar and returns the ID. Call on “widgets_init” action.

<?php register_sidebar( $args ); ?>

Parameters

name – Sidebar name (default is localized ‘Sidebar’ and numeric ID).

id – Sidebar id – Must be all in lowercase, with no spaces (default is a numeric auto-incremented ID).

description – Text description of what/where the sidebar is. Shown on widget management screen. (Since 2.9) (default: empty)

class – CSS class name to assign to the widget HTML (default: empty).
every title (default: “</h2>\n”).

Parameters