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

Checks if a meta key is registered.

Parameters

$object_type

(string) (Required) Type of object metadata is for. Accepts 'post', 'comment', 'term', 'user', or any other object type with an associated meta table.

$meta_key

(string) (Required) Metadata key.

$object_subtype

(string) (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 ] );
}

Uses

Uses Description
wp-includes/meta.php: get_registered_meta_keys()

Retrieves a list of registered meta keys for an object type.

Used By

Used By Description
wp-includes/meta.php: unregister_meta_key()

Unregisters a meta key from the list of registered keys.
wp-includes/meta.php: get_registered_metadata()

Retrieves registered metadata for a specified object.

Changelog

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

© 2003–2019 WordPress Foundation
Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/registered_meta_key_exists