Add a sortable user Id column into WordPress Users table

Sometimes it is useful to find the user_id of each user you have in your WordPress site.  This is especially helpful if you have a multisite with a lots of users.  Something like this:


In order to have that kind of functionality,  you can add the following code in your theme’s functions.php.
If you have a multisite installation the ID column will be only displayed in the network users admin page and not in each subsite’s users admin table.