get_metadata_default( string $meta_type, int $object_id, string $meta_key, bool $single = false ): mixed

699function get_metadata_default( $meta_type, $object_id, $meta_key, $single = false ) {700	if ( $single ) {701		$value = '';702	} else {703		$value = array();704	}705 706	/**707	 * Filters the default metadata value for a specified meta key and object.708	 *709	 * The dynamic portion of the hook name, `$meta_type`, refers to the meta object type710	 * (post, comment, term, user, or any other type with an associated meta table).711	 *712	 * Possible filter names include:713	 *714	 *  - `default_post_metadata`715	 *  - `default_comment_metadata`716	 *  - `default_term_metadata`717	 *  - `default_user_metadata`718	 *719	 * @since 5.5.0720	 *721	 * @param mixed  $value     The value to return, either a single metadata value or an array722	 *                          of values depending on the value of `$single`.723	 * @param int    $object_id ID of the object metadata is for.724	 * @param string $meta_key  Metadata key.725	 * @param bool   $single    Whether to return only the first value of the specified `$meta_key`.726	 * @param string $meta_type Type of object metadata is for. Accepts 'post', 'comment', 'term', 'user',727	 *                          or any other object type with an associated meta table.728	 */729	$value = apply_filters( "default_{$meta_type}_metadata", $value, $object_id, $meta_key, $single, $meta_type );730 731	if ( ! $single && ! wp_is_numeric_array( $value ) ) {732		$value = array( $value );733	}734 735	return $value;736}