Fetch data from custom post.

<?php
//Featured Case Studies
add_shortcode('case_study', 'case_study_home');
function case_study_home()
{
    ob_start();
    echo '<div id="feature-case-study">';

    $args = array(
        'post_type' => 'case-studies',
        'posts_per_page' => 4,
        'featured' => 'yes',
        'order' => 'rand'
    );
    $resData = new WP_Query($args);
    if ($resData->have_posts()) :
        while ($resData->have_posts()) :
            $resData->the_post();
            ?>
            <div>
                <div class="col-md-6 col-lg-6 col-xs-12 element1">
                    <?php
                    $image = get_the_post_thumbnail(get_the_ID(), '', array('class' => 'img-responsive'));
                    echo $image;
                    ?>
                </div>
                <div class="col-md-6 col-lg-6 col-xs-12"><!------SVG 1 of 2------>
                    <div class="box-item">
                         <?php  $categories = get_the_category();
                                foreach ($categories as $cat) {
                                        echo '<a href="' . esc_url(get_category_link($cat->term_id)) . '" class="button_hover tag_btn">' . esc_html($cat->name) . '</a>';
                                    } ?>
                        <?php the_title('<h4>', '</h4>'); ?>
                        <?php the_content(__('(more...)')); ?>
                        <a href="<?php the_permalink(); ?>" class="btn btn-yellow">Read the case study</a>
                    </div>
                </div>
            </div>
        <?php endwhile; ?>
        <?php
    else:
        echo '<h2>No case studies found<h2>';
    endif;
    echo '</div>';
    wp_reset_postdata();
    return ob_get_clean();
}

?>