how to check if custom post type exists in wordpress

Question

you can do it with Function post_type_exists
https://codex.wordpress.org/Function_Reference/post_type_exists

Examples

if ( post_type_exists( 'book' ) ) {
   echo 'the Book post type exists';
}
$exists = post_type_exists( 'post' );
// returns true

$exists = post_type_exists( 'page' );
// returns true

$exists = post_type_exists( 'book' );
// returns true if book is a registered post type

$exists = post_type_exists( 'xyz' );
// returns false if xyz is not a registered post type