$catids = $_POST[\'artticle_category\'];
/*
 * If the ids are coming from the database or another source, we would 
 * need to make sure these were integers or convert them to interger using intval:
 */

$catids = array_map( \'intval\', $catids );
$catids = array_unique( $catids );
$taxonomy = \'articles_category\';
$post_id = \'1\';

$term_taxonomy_ids = wp_set_object_terms( $post_id, $catids , $taxonomy );