I’m still not one hundred percent sure where and what needs to be displayed.
If you need to show the current single post’s category, you’ll need to use get_the_category in stead of the_category as the_category needs to be called inside the loop. You can use get_the_category as follow (Remember to use the global $post to retrieve the post ID)
<?php
global $post;
$categories = get_the_category($post->ID);
var_dump($categories);
?>
If you need to get the category name on a category page, you can use get_query_var('cat') to retrieve info about the current category page.
Here is an example of the breadcrumbs that I use on my site.
if ( ! function_exists( 'pietergoosen_breadcrumbs' ) ) :
function pietergoosen_breadcrumbs() {
/* === OPTIONS === */
$text['home'] = _x( 'Home', 'Home', 'pietergoosen' ); // text for the 'Home' link
$text['category'] = __( 'Archive by Category "%s"', 'pietergoosen' ); // text for a category page
$text['search'] = __( 'Search Results for "%s" Query', 'pietergoosen' ); // text for a search results page
$text['tag'] = __( 'Posts Tagged "%s"', 'pietergoosen' ); // text for a tag page
$text['author'] = __( 'Posts Posted by %s', 'pietergoosen' ); // text for an author page
$text['404'] = __( 'Error 404', 'pietergoosen' ); // text for the 404 page
$show_current = 1; // 1 - show current post/page/category title in breadcrumbs, 0 - don't show
$show_on_home = 0; // 1 - show breadcrumbs on the homepage, 0 - don't show
$show_home_link = 1; // 1 - show the 'Home' link, 0 - don't show
$show_title = 1; // 1 - show the title for the links, 0 - don't show
$delimiter=" » "; // delimiter between crumbs
$before="<span class="current">"; // tag before the current crumb
$after="</span>"; // tag after the current crumb
/* === END OF OPTIONS === */
global $post;
$here_text = __('You are currently here! » ', 'pietergoosen');
$home_link = home_url("https://wordpress.stackexchange.com/");
$link_before="<span typeof="v:Breadcrumb">";
$link_after="</span>";
$link_attr=" rel="v:url" property="v:title"";
$link = $link_before . '<a' . $link_attr . ' href="https://wordpress.stackexchange.com/questions/159519/%1$s">%2$s</a>' . $link_after;
if (isset($post)){
$parent_id = $parent_id_2 = $post->post_parent;
}
$frontpage_id = get_option('page_on_front');
if (is_home() || is_front_page()) {
if ($show_on_home == 1) echo '<div class="breadcrumb"><a href="' . $home_link . '">' . $text['home'] . '</a></div>';
} else {
echo '<div class="breadcrumb">';
if ($show_home_link == 1) {
echo $here_text . '<a href="' . $home_link . '" rel="v:url" property="v:title">' . $text['home'] . '</a>';
if ($frontpage_id == 0 || $parent_id != $frontpage_id) echo $delimiter;
}
if ( is_category() ) {
$this_cat = get_category(get_query_var('cat'), false);
if ($this_cat->parent != 0) {
$cats = get_category_parents($this_cat->parent, TRUE, $delimiter);
if ($show_current == 0) $cats = preg_replace("#^(.+)$delimiter$#", "$1", $cats);
$cats = str_replace('<a', $link_before . '<a' . $link_attr, $cats);
$cats = str_replace('</a>', '</a>' . $link_after, $cats);
if ($show_title == 0) $cats = preg_replace('/ title="(.*?)"https://wordpress.stackexchange.com/", '', $cats);
echo $cats;
}
if ($show_current == 1) echo $before . sprintf($text['category'], single_cat_title('', false)) . $after;
} elseif ( is_search() ) {
echo $before . sprintf($text['search'], get_search_query()) . $after;
} elseif ( is_day() ) {
echo sprintf($link, get_year_link(get_the_time('Y')), get_the_time('Y')) . $delimiter;
echo sprintf($link, get_month_link(get_the_time('Y'),get_the_time('m')), get_the_time('F')) . $delimiter;
echo $before . get_the_time('d') . $after;
} elseif ( is_month() ) {
echo sprintf($link, get_year_link(get_the_time('Y')), get_the_time('Y')) . $delimiter;
echo $before . get_the_time('F') . $after;
} elseif ( is_year() ) {
echo $before . get_the_time('Y') . $after;
} elseif ( is_single() && !is_attachment() ) {
if ( get_post_type() != 'post' ) {
$post_type = get_post_type_object(get_post_type());
$slug = $post_type->rewrite;
printf($link, $home_link . "https://wordpress.stackexchange.com/" . $slug['slug'] . "https://wordpress.stackexchange.com/", $post_type->labels->singular_name);
if ($show_current == 1) echo $delimiter . $before . get_the_title() . $after;
} else {
$cat = get_the_category(); $cat = $cat[0];
$cats = get_category_parents($cat, TRUE, $delimiter);
if ($show_current == 0) $cats = preg_replace("#^(.+)$delimiter$#", "$1", $cats);
$cats = str_replace('<a', $link_before . '<a' . $link_attr, $cats);
$cats = str_replace('</a>', '</a>' . $link_after, $cats);
if ($show_title == 0) $cats = preg_replace('/ title="(.*?)"https://wordpress.stackexchange.com/", '', $cats);
echo $cats;
if ($show_current == 1) echo $before . get_the_title() . $after;
}
} elseif ( !is_single() && !is_page() && get_post_type() != 'post' && !is_404() ) {
$post_type = get_post_type_object(get_post_type());
echo $before . $post_type->labels->singular_name . $after;
} elseif ( is_attachment() ) {
$parent = get_post($parent_id);
$cat = get_the_category($parent->ID); $cat = $cat[0];
$cats = get_category_parents($cat, TRUE, $delimiter);
$cats = str_replace('<a', $link_before . '<a' . $link_attr, $cats);
$cats = str_replace('</a>', '</a>' . $link_after, $cats);
if ($show_title == 0) $cats = preg_replace('/ title="(.*?)"https://wordpress.stackexchange.com/", '', $cats);
echo $cats;
printf($link, get_permalink($parent), $parent->post_title);
if ($show_current == 1) echo $delimiter . $before . get_the_title() . $after;
} elseif ( is_page() && !$parent_id ) {
if ($show_current == 1) echo $before . get_the_title() . $after;
} elseif ( is_page() && $parent_id ) {
if ($parent_id != $frontpage_id) {
$breadcrumbs = array();
while ($parent_id) {
$page = get_page($parent_id);
if ($parent_id != $frontpage_id) {
$breadcrumbs[] = sprintf($link, get_permalink($page->ID), get_the_title($page->ID));
}
$parent_id = $page->post_parent;
}
$breadcrumbs = array_reverse($breadcrumbs);
for ($i = 0; $i < count($breadcrumbs); $i++) {
echo $breadcrumbs[$i];
if ($i != count($breadcrumbs)-1) echo $delimiter;
}
}
if ($show_current == 1) {
if ($show_home_link == 1 || ($parent_id_2 != 0 && $parent_id_2 != $frontpage_id)) echo $delimiter;
echo $before . get_the_title() . $after;
}
} elseif ( is_tag() ) {
echo $before . sprintf($text['tag'], single_tag_title('', false)) . $after;
} elseif ( is_author() ) {
global $author;
$userdata = get_userdata($author);
echo $before . sprintf($text['author'], $userdata->display_name) . $after;
} elseif ( is_404() ) {
echo $before . $text['404'] . $after;
}
if ( get_query_var('paged') ) {
if ( is_category() || is_day() || is_month() || is_year() || is_search() || is_tag() || is_author() ) echo ' (';
echo __(' » Page', 'pietergoosen') . ' ' . get_query_var('paged');
if ( is_category() || is_day() || is_month() || is_year() || is_search() || is_tag() || is_author() ) echo ')';
}
echo '</div><!-- .breadcrumbs -->';
}
}
endif;
NOTE: I’ve copied this function from somewhere a year or two ago without adding author credit (bad me), so I can’t remember who the original author was. If you, the author, see this post, please reply so that I can add full credit to you)