list all child categories that apply to current post even if those cats are empty?

Question

list all child categories that apply to current post even if those cats are empty? everything I tried just shows "post not found" -

Have alphabetical listing and trying to create

A B C D hyperlinked listing

A - All categories that child of A B - All categories that child of B etc

Answer 1

get_the_category()

get_categories()

get_category_link()

<?php 
echo '<ul>';
foreach(get_the_category() as $cat) { 
    echo '<li><a href="'.get_category_link($cat->term_id).'">'.$cat->name.'</a>';
    $sub_cats = get_categories('parent='.$cat->term_id.'&hide_empty=0');
    if($sub_cats) {
        echo '<ul>';
        foreach($sub_cats as $sub_cat) {
        echo '<li><a href="'.get_category_link($sub_cat->term_id).'">'.$sub_cat->name.'</a></li>';
        }
        echo '</ul>';
    echo '</li>';
    }
}
echo '</ul>';
?>

edit: for a list of sub categories in a category archive, try this code:

<?php  
$cat = get_query_var('cat');
$cat_list = wp_list_categories('child_of='.$cat.'&hide_empty=0&title_li=&echo=0');
    if($cat_list) {
    echo 'Sub-category List <ul>';
    echo $cat_list;
    echo '</ul>';
    }
?>

wp_list_categories()