Using WordPress ‘count_users()’ PHP function
Counts number of users who have each of the user roles.
WordPress
Using WordPress ‘doing_action()’ PHP function
Returns whether or not an action hook is currently being processed.
Using WordPress ‘core_upgrade_preamble()’ PHP function
Display upgrade WordPress for downloading latest or upgrading automatically form.
Using WordPress ‘filter_block_content()’ PHP function
Filters and sanitizes block content to remove non-allowable HTML from parsed block attribute values.