How to add noindex to headings without posts in WordPress

You may have a situation where you have created several headings, but have not yet added posts to them. You probably don’t want empty categories without posts to be indexed by search engines. You can use wp_robots filter to add noindex to the robots meta tag:

add_filter( 'wp_robots', 'wpz_wp_robots' );
function wpz_wp_robots( $robots ) {

	if ( is_archive() && ! have_posts() ) {
		$robots['noindex']  = true;
		$robots['nofollow'] = true;
	}

	return $robots;
}