Add category class to a post card

There’s some way to add a category class (id or slug) to the post card?
I want to modify the style if the post is in one or other category.
I will be something like this:

function wpappninja_show_card($content_post) {
	?>
	<div class="card wpappninja-card-header-pic wpappninja-card post -->category<--" id="post-<?php echo $content_post->ID; ?>">

• This topic was modified 4 years, 6 months ago by Kim Soler.