List categories with alphabetical headings

I found a code to list my categories in 2 columns but now I want it to show the alphabetical headings for example http://www.zomganime.com/anime-series-list/. So does anyone know how? don't say use a plugin because I'm trying to use less plugins to save performance.

<?php
$cats = explode("<br />",wp_list_categories('title_li=&echo=0&depth=1&style=none'));
$cat_n = count($cats) - 1;
for ($i=0;$i<$cat_n;$i++):
if ($i<$cat_n/2):
$cat_left = $cat_left.'<li>'.$cats[$i].’</li>’;
elseif ($i>=$cat_n/2):
$cat_right = $cat_right.’<li>’.$cats[$i].’</li>’;
endif;
endfor;
?>
<ul class=”left”>
<?php echo $cat_left;?>
</ul>
<ul class=”right”>
<?php echo $cat_right;?>
</ul>

Code (markup):

 

Use the "orderby" parameter in the wp_list_categories tag.

More info on it can be found here.

 

The orderby is not what I'm looking for. It needs to show the alphabetical heading, did you have a look at the example? I want the categories to display like this

A
apple
air
acting
artist

B
blue
blueberry
batman
boy

 

Sorry, I missed your example. You'll have to use a plugin for that (even though you don't want to). AZIndex is one that will give output like you want.

 

Geekly Weekly has a page order and a link order and a category order plugin that works with WP 2.8. You may have to make slight modifications to your Template.. but it's not that hard.

 

I don't want to use a plugin I would want it as a template code

 

<?php
$cats = explode("<br/>", wp_list_categories('title_li=&echo=0&depth=1&style=none'));
$cat_n = count($cats) - 1;
for ($i=0; $i<$cat_n; $i++) {
    $this_letter = strtoupper(substr(trim(strip_tags($cats[$i])), 0, 1));
    $this_letter = ctype_alpha($this_letter) ? $this_letter : "#"; // Replace '#' with your desired nonalphabetic heading
    if ($i<$cat_n/2) {
        $cat_left .= ($this_letter != $last_letter) ? "<li>{$this_letter}</li>" : "";
        $cat_left .= "<li>{$cats[$i]}</li>";
    } else {
        $cat_right .= ($this_letter != $last_letter) ? "<li>{$this_letter}</li>" : "";
        $cat_right .= "<li>{$cats[$i]}</li>";
    }
    $last_letter = $this_letter;
}
?>

PHP:

Try this out, contact me via IM if you get any problems

 

Why bothering? There is already written plugin for this:

http://www.dagondesign.com/articles/multi-column-category-list-plugin-for-wordpress/

 

Did you not read my first post I said I don't want to use a plugin cause I want to save performance on my site, anyway I got the code working