ID of the current post in the WordPress loop or the post being displayed is stored in this global variable. It is set in the
setup_postdata($post) defined in [wordpress root folder]/wp-includes/functions.php.
WordPress provides the function
the_ID() that can be used inside the WordPress loop to display the post ID. However, the plugin and theme authors can access this global variable to access the post ID. It can be used to get a post using
Back to full list of global variables.