wp_list_pluck Example

gistfile1.aw

<?php
// Take from posts-to-posts (http://scribu.net/wordpress/posts-to-posts)
public function get_related( $post_id, $extra_qv = array() ) {
    $post_id = (array) $post_id;

    $connected = $this->get_connected( $post_id, $extra_qv );
    if ( !$connected )
        return false;

    if ( !$connected->have_posts() )
        return $connected;

    $connected_ids = wp_list_pluck( $connected->posts, 'ID' );

    return $this->get_connected( $connected_ids, array(
        'post__not_in' => $post_id,
    ) );
}