Creating a variable name which has, as part, data from an array

I am creating several CPTs for a site. To register and activate, I go through the same process for each one. The process involves creating variables, all of which are in the same form.

I'd like to be able to loop through these using an array with the different CPT names and adding them to variable names.

For example, I'd like to have an array:

$CPT = array ('book', 'movie', 'event');

and do things in the loop like create:
$book_custom_post_type
$movie_custom_post_type
$event_custom_post_type

I'd appreciate guidance on how to do this!

Thanks!

Laura