Title: nav_menu_submenu_css_class
Published: June 15, 2017
Last modified: April 28, 2025

---

# apply_filters( ‘nav_menu_submenu_css_class’, string[] $classes, stdClass $args, int $depth )

## In this article

 * [Parameters](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#changelog)
 * [User Contributed Notes](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#user-contributed-notes)

[ Back to top](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#wp--skip-link--target)

Filters the CSS class(es) applied to a menu list element.

## 󠀁[Parameters](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#parameters)󠁿

 `$classes`string[]

Array of the CSS classes that are applied to the menu `<ul>` element.

`$args`stdClass

An object of `wp_nav_menu()` arguments.

`$depth`int

Depth of menu item. Used for padding.

## 󠀁[Source](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#source)󠁿

    ```php
    $class_names = implode( ' ', apply_filters( 'nav_menu_submenu_css_class', $classes, $args, $depth ) );
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-walker-nav-menu.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/class-walker-nav-menu.php#L92)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/class-walker-nav-menu.php#L92-L92)

## 󠀁[Related](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#related)󠁿

| Used by | Description | 
| [Walker_Nav_Menu::start_lvl()](https://developer.wordpress.org/reference/classes/walker_nav_menu/start_lvl/)`wp-includes/class-walker-nav-menu.php` |

Starts the list before the elements are added.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#changelog)󠁿

| Version | Description | 
| [4.8.0](https://developer.wordpress.org/reference/since/4.8.0/) | Introduced. |

## 󠀁[User Contributed Notes](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#user-contributed-notes)󠁿

 1.  [Skip to note 2 content](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/?output_format=md#comment-content-3873)
 2.   [wpuzman](https://profiles.wordpress.org/wpuzman/)  [  6 years ago  ](https://developer.wordpress.org/reference/hooks/nav_menu_submenu_css_class/#comment-3873)
 3. [You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fhooks%2Fnav_menu_submenu_css_class%2F%23comment-3873)
    Vote results for this note: 1[You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fhooks%2Fnav_menu_submenu_css_class%2F%23comment-3873)
 4.     ```php
        function wpdocs_custom_dropdown_class( $classes ) {
        	$classes[] = 'dropdown';
    
        	return $classes;
        }
    
        add_filter( 'nav_menu_submenu_css_class', 'wpdocs_custom_dropdown_class' );
        ```
    
 5.  [Log in to add feedback](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fhooks%2Fnav_menu_submenu_css_class%2F%3Freplytocom%3D3873%23feedback-editor-3873)

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