in_category( int|string|int[]|string[] $category, int|WP_Post $post = null )

Checks if the current post is within any of the given categories.


Description

The given categories are checked against the post’s categories’ term_ids, names and slugs.
Categories given as integers will only be checked against the post’s categories’ term_ids.

Prior to v2.5 of WordPress, category names were not supported.
Prior to v2.7, category slugs were not supported.
Prior to v2.7, only one category could be compared: in_category( $single_category ).
Prior to v2.7, this function could only be used in the WordPress Loop.
As of 2.7, the function can be used anywhere if it is provided a post ID or post object.

For more information on this and similar theme functions, check out the Conditional Tags article in the Theme Developer Handbook.


Parameters

$category

(Required) Category ID, name, slug, or array of such to check against.

$post

(Optional) Post to check. Defaults to the current post.

Default value: null


Return

(bool) True if the current post is in any of the given categories.


Source

File: wp-includes/category-template.php

function in_category( $category, $post = null ) {
	if ( empty( $category ) )
		return false;

	return has_category( $category, $post );
}

Changelog

Changelog
Version Description
2.7.0 The $post parameter was added.
1.2.0 Introduced.