WordPress at a glance
function is not described

upgrade_420() WP 4.2.0

Execute changes made in WordPress 4.2.0.

  • Global. Int. $wp_current_db_version
  • Global. wpdb. $wpdb

No Hooks.

Return

Nothing (null).

Usage

upgrade_420();

Code of upgrade 420: wp-admin/includes/upgrade.php WP 5.2.2

<?php
function upgrade_420() {}