How to exclude a category name from showing?

Question

So I'm trying this code:

<?php
global $post;
$my_query = new WP_Query('showposts=8&category_name=featured');

while ($my_query->have_posts()):
    $my_query->the_post();
    $do_not_duplicate = $post->ID;
    $category = get_the_category();
    $content = get_the_content();
    $image = wp_get_attachment_image_src(get_post_thumbnail_id($post->ID) , 'main-thumbs');
    $tn_id = get_post_thumbnail_id($post->ID);
    $img = wp_get_attachment_image_src($tn_id, 'main-thumbs');
    $width = $img[1];
    $height = $img[2];
?>
....
<div class="cat-square <?php
    echo esc_html($category[0]->slug) ?>">

with this, I can style a generic div (cat-square) and then add some additional styling depending on the category the post is in. So far so good, this work as a charm. Exception made that categories, which are all scientific disciplines, can also belong to Featured category . So, sometimes the category (let's say Physics) is replaced by Featured category.

How can prevent this from happening? Please note that I don't mean to exclude the post itself, only the Featured category nicename and slug

Answer 1

The function get_the_category is returning you an array of objects (see codex for more info), so if the post has more than one term assigned, then you are just outputting the first one.

So I think that doing a foreach loop will solve your problem:

foreach ($category as $cat) {
    if ($cat->slug != 'featured') {
        echo esc_html($cat->slug);
    }
}

Hope it helps!