wordpress query show all categories from post code example

Example 1: wordpress display post categories

<?php the_terms( $post->ID, 'topics', 'Topics: ', ', ', ' ' ); ?>

Example 2: wp get all post categories

$categories = get_categories();
foreach($categories as $category) {
   echo '<div class="col-md-4"><a href="' . get_category_link($category->term_id) . '">' . $category->name . '</a></div>';
}