in_category( int|string|array $category, int|object $post = null )

Check 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.


Parameters

$category

(Required) Category ID, name or slug, or array of said.

$post

(Optional) Post to check instead of the current post. (since WP-2.7.0)

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
WP-1.2.0 Introduced.