Access queried post ID in WP_Query

Question

WordPress has quite a few global variables to choose from which may help. For example, you can use the global $post to get first post in the query.

global $post;
$my_meta_value = get_post_meta( $post->ID, '_another_meta_key', true );

Or you could reach directly into the $wp_query object posts array and grab the first post:

global $wp_query;

if( ! empty( $wp_query->posts ) ) {
    $my_meta_value = get_post_meta( $wp_query->posts[0]->ID, '_another_meta_key', true );
}