add_shortcode( 'objectx-pages-list', 'objectx_pages_list_func' );
function objectx_pages_list_func( $atts ) {
global $post;
ob_start();
extract( shortcode_atts( array('ids' => '1186'), $atts ) );
$id_array = explode(',', $ids);
$pages_query = new WP_Query( array(
    'post_type' => 'page',
    'post__in' => $id_array,
    'order' => 'ASC',
    'orderby' => 'title',
) );
if ( $pages_query->have_posts() ) { ?>
<div class="carousel-wrapper">
<div class="owl-carousel owl-theme carousel-1" id="carousel-rooms">
<?php while ( $pages_query->have_posts() ) : $pages_query->the_post();
$featured_image = wp_get_attachment_url( get_post_thumbnail_id($post->ID) );
?>
<div <?php post_class('item'); ?> id="post-<?php the_ID(); ?>">
    <div class="row">
        <div class="col-md-7">
            <div class="img-rooms">
                <a href="<?php the_permalink(); ?>">
                <img class="img-responsive wp-post-image" src="<?php echo $featured_image; ?>"></a>
            </div>
        </div>
    <div class="col-md-5">
        <div class="detail-rooms">
            <h2 class="title-room "><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
            <?php the_excerpt(); ?>
        </div>
    </div>
    </div>
</div>
<?php endwhile; ?>
</div>
</div>
<?php $myvariable_pages = ob_get_clean();
wp_reset_postdata();
return $myvariable_pages;
    }
}

[objectx-pages-list id="15,16,17"]
[objectx-pages-list ids="25,26,27"]