get post id by category id in wordpress code example
Example 1: wordpress get post id
// Retrieve the ID of the current item in the WordPress Loop.
get_the_ID()
Example 2: how to get category from post id
get_the_category($post->ID)
Example 3: wordpress get post by id
$post = get_post( 123 ); // Where 123 is the ID
$output = apply_filters( 'the_content', $post->post_content );