WordPress: Add a hashtag to the category-slugname

Question

I'm trying to find a solution to remove e.g. http://website/drinks/, then add a hashtag at the beginning of the categories-slugname e.g. #coffee.

Current situation:

<ul>
<li class="cat-item-1"><a href="http://website/drinks/coffee/">Coffee</a></li>
<li class="cat-item-2"><a href="http://website/drinks/tea/">Tea</a></li>
</ul>

Desired situation:

<ul>
<li class="cat-item-1"><a href="#coffee">Coffee</a></li>
<li class="cat-item-2"><a href="#tea">Tea</a></li>
</ul>

The solution must be codded in functions.php of my WordPress theme. I'm not a master at coding, but I've founded a way to add a hash at the ending of the URL.

add_filter('wp_list_categories', 'filter_categories', 10, 2);

function filter_categories($output, $args=array()){
      return preg_replace('/(\<a\shref=\"?[^\>]+?)\"/', '$1#"', $output);
}

Output:

<ul>
<li class="cat-item-1"><a href="http://website/drinks/coffee/#">Coffee</a></li>
<li class="cat-item-2"><a href="http://website/drinks/tea/#">tea</a></li>
</ul>

Unfortunately this is for away from my desired situation... Can anyone please help me out?

Answer 1

Try this:

add_filter('wp_list_categories', function($html, $args) {

    $pattern = '/https?:\/\/([^\/]+)\/([^\/]+)\/?/';

    $html = preg_replace($pattern, '#', $html);

    return preg_replace('/\/["\']/', '"', $html);

}, 10, 2);