wp_get_post_categories( int $post_id, array $args = array() )
Retrieve the list of categories for a post.
Description
Compatibility layer for themes and plugins. Also an easy layer of abstraction away from the complexity of the taxonomy layer.
See also
Parameters
- $post_id
-
(int) (Optional) The Post ID. Does not default to the ID of the global $post. Default 0.
- $args
-
(array) (Optional) Category query parameters. See WP_Term_Query::__construct() for supported arguments.
Default value: array()
Return
(array|WP_Error) List of categories. If the $fields argument passed via $args is 'all' or 'all_with_object_id', an array of WP_Term objects will be returned. If $fields is 'ids', an array of category ids. If $fields is 'names', an array of category names. WP_Error object if 'category' taxonomy doesn't exist.
Source
File: wp-includes/post.php
function wp_get_post_categories( $post_id = 0, $args = array() ) {
$post_id = (int) $post_id;
$defaults = array( 'fields' => 'ids' );
$args = wp_parse_args( $args, $defaults );
$cats = wp_get_object_terms( $post_id, 'category', $args );
return $cats;
}
Changelog
| Version | Description |
|---|---|
| 2.1.0 | Introduced. |
More Information
The results from wp_get_post_categories() aren’t cached which will result in a database call being made every time this function is called. Use this function with care. For performance, functions like get_the_category() should be used to return categories attached to a post.
The example below shows how categories are retrieved, and then additional information is retrieved for each category.
$post_categories = wp_get_post_categories( $post_id ); $cats = array(); foreach($post_categories as $c){ $cat = get_category( $c ); $cats[] = array( 'name' => $cat->name, 'slug' => $cat->slug ); }