I want to learn if it is possible to assign different classes to each category item in listing

I want it to give different css to each individual item.

1. item will have K2item-1 2. item will have K2item-2 etc.

Yes through template overrides.

You can echo the category name or id or even a pattern in the the #K2container element as classnames.

More about template overrides can be found here: getk2.org/documentation/tutorials/174-templating-with-k2-and-the-concepts-of-sub-templates

I opened and add

<div class="hizmet<?php echo $this->item->id; ?>"

so I will have unique class to all my items in categori listing


thanks for the itemid idea :)

This will produce a different class per item.
You can also echo the category's id, to have a more common and generic class.