Title: Walker_Nav_Menu_Checklist::start_lvl
Published: April 25, 2014
Last modified: May 20, 2026

---

# Walker_Nav_Menu_Checklist::start_lvl( string $output, int $depth, stdClass $args = null )

## In this article

 * [Description](https://developer.wordpress.org/reference/classes/walker_nav_menu_checklist/start_lvl/?output_format=md#description)
    - [See also](https://developer.wordpress.org/reference/classes/walker_nav_menu_checklist/start_lvl/?output_format=md#see-also)
 * [Parameters](https://developer.wordpress.org/reference/classes/walker_nav_menu_checklist/start_lvl/?output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/classes/walker_nav_menu_checklist/start_lvl/?output_format=md#source)
 * [Changelog](https://developer.wordpress.org/reference/classes/walker_nav_menu_checklist/start_lvl/?output_format=md#changelog)

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

Starts the list before the elements are added.

## 󠀁[Description](https://developer.wordpress.org/reference/classes/walker_nav_menu_checklist/start_lvl/?output_format=md#description)󠁿

### 󠀁[See also](https://developer.wordpress.org/reference/classes/walker_nav_menu_checklist/start_lvl/?output_format=md#see-also)󠁿

 * [Walker_Nav_Menu::start_lvl()](https://developer.wordpress.org/reference/classes/Walker_Nav_Menu/start_lvl/)

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

 `$output`stringrequired

Used to append additional content (passed by reference).

`$depth`intrequired

Depth of page. Used for padding.

`$args`stdClassoptional

Not used.

Default:`null`

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

    ```php
    public function start_lvl( &$output, $depth = 0, $args = null ) {
    	$indent  = str_repeat( "\t", $depth );
    	$output .= "\n$indent<ul class='children'>\n";
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-admin/includes/class-walker-nav-menu-checklist.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.0/src/wp-admin/includes/class-walker-nav-menu-checklist.php#L37)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.0/src/wp-admin/includes/class-walker-nav-menu-checklist.php#L37-L40)

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

| Version | Description | 
| [3.0.0](https://developer.wordpress.org/reference/since/3.0.0/) | Introduced. |

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