Required Wordpress freelancer for ACF relationship field get IDs job

I am using an ACF relationship field to select posts or pages, I need to get the IDs of these and put them in an array.

At the moment I am just manually entering the IDs into my array like so:
if ( is_page(array( '2','7' )) ) { }

This needs to populate automatically based on the IDs of the posts or pages selected from the relationship field.

Skills & Expertise Required

Wordpress