Title: Walker_CategoryDropdown
Published: April 25, 2014
Last modified: April 28, 2025

---

# class Walker_CategoryDropdown {}

## In this article

 * [Description](https://developer.wordpress.org/reference/classes/walker_categorydropdown/?output_format=md#description)
    - [See also](https://developer.wordpress.org/reference/classes/walker_categorydropdown/?output_format=md#see-also)
 * [Methods](https://developer.wordpress.org/reference/classes/walker_categorydropdown/?output_format=md#methods)
 * [Source](https://developer.wordpress.org/reference/classes/walker_categorydropdown/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/walker_categorydropdown/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/walker_categorydropdown/?output_format=md#changelog)

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

Core class used to create an HTML dropdown list of Categories.

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

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

 * [Walker](https://developer.wordpress.org/reference/classes/walker/)

## 󠀁[Methods](https://developer.wordpress.org/reference/classes/walker_categorydropdown/?output_format=md#methods)󠁿

| Name | Description | 
| [Walker_CategoryDropdown::start_el](https://developer.wordpress.org/reference/classes/walker_categorydropdown/start_el/) | Starts the element output. |

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

    ```php
    class Walker_CategoryDropdown extends Walker {

    	/**
    	 * What the class handles.
    	 *
    	 * @since 2.1.0
    	 * @var string
    	 *
    	 * @see Walker::$tree_type
    	 */
    	public $tree_type = 'category';

    	/**
    	 * Database fields to use.
    	 *
    	 * @since 2.1.0
    	 * @todo Decouple this
    	 * @var string[]
    	 *
    	 * @see Walker::$db_fields
    	 */
    	public $db_fields = array(
    		'parent' => 'parent',
    		'id'     => 'term_id',
    	);

    	/**
    	 * Starts the element output.
    	 *
    	 * @since 2.1.0
    	 * @since 5.9.0 Renamed `$category` to `$data_object` and `$id` to `$current_object_id`
    	 *              to match parent class for PHP 8 named parameter support.
    	 *
    	 * @see Walker::start_el()
    	 *
    	 * @param string  $output            Used to append additional content (passed by reference).
    	 * @param WP_Term $data_object       Category data object.
    	 * @param int     $depth             Depth of category. Used for padding.
    	 * @param array   $args              Uses 'selected', 'show_count', and 'value_field' keys, if they exist.
    	 *                                   See wp_dropdown_categories().
    	 * @param int     $current_object_id Optional. ID of the current category. Default 0.
    	 */
    	public function start_el( &$output, $data_object, $depth = 0, $args = array(), $current_object_id = 0 ) {
    		// Restores the more descriptive, specific name for use within this method.
    		$category = $data_object;

    		$pad = str_repeat( ' ', $depth * 3 );

    		/** This filter is documented in wp-includes/category-template.php */
    		$cat_name = apply_filters( 'list_cats', $category->name, $category );

    		if ( isset( $args['value_field'] ) && isset( $category->{$args['value_field']} ) ) {
    			$value_field = $args['value_field'];
    		} else {
    			$value_field = 'term_id';
    		}

    		$output .= "\t<option class=\"level-$depth\" value=\"" . esc_attr( $category->{$value_field} ) . '"';

    		// Type-juggling causes false matches, so we force everything to a string.
    		if ( (string) $category->{$value_field} === (string) $args['selected'] ) {
    			$output .= ' selected="selected"';
    		}
    		$output .= '>';
    		$output .= $pad . $cat_name;
    		if ( $args['show_count'] ) {
    			$output .= '&nbsp;&nbsp;(' . number_format_i18n( $category->count ) . ')';
    		}
    		$output .= "</option>\n";
    	}
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-walker-category-dropdown.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/class-walker-category-dropdown.php#L17)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/class-walker-category-dropdown.php#L17-L87)

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

| Uses | Description | 
| [Walker](https://developer.wordpress.org/reference/classes/walker/)`wp-includes/class-wp-walker.php` |

A class for displaying various tree-like structures.

  |

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

| Version | Description | 
| [2.1.0](https://developer.wordpress.org/reference/since/2.1.0/) | Introduced. |

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