registered_meta_key_exists( string $object_type, string $meta_key, string $object_subtype = '' )

Checks if a meta key is registered.


Parameters

$object_type

(Required) The type of object.

$meta_key

(Required) The meta key.

$object_subtype

(Optional) The subtype of the object type.

Default value: ''


Return

(bool) True if the meta key is registered to the object type and, if provided, the object subtype. False if not.


Source

File: wp-includes/meta.php

function registered_meta_key_exists( $object_type, $meta_key, $object_subtype = '' ) {
	$meta_keys = get_registered_meta_keys( $object_type, $object_subtype );

	return isset( $meta_keys[ $meta_key ] );
}


Changelog

Changelog
Version Description
WP-4.9.8 The $object_subtype parameter was added.
WP-4.6.0 Introduced.