Owl slider adds class "last" to every 4th item in slider

Ok sorry its me again,
also in content-product-slider.php there is this part that says that there should be 4 columns:

// Store column count for displaying the grid
if ( empty( $woocommerce_loop['columns'] ) )
	$woocommerce_loop['columns'] = apply_filters( 'loop_shop_columns', 4 );

What is this code for and how can I edit it in order to set the colums dynamically?

Thank you, but I don’t want to use grid, I want to use slider…

No, it’s very confusing.
If I add the shortcode [etheme_products] to a page, classes are set like this:
1. Item class FIRST
2. Item
3. Item
4. Item class LAST
5. Item class FIRST
[…]

But if I add the same shortcode on product description field of a product, the classes are set like this:
1. Item
2. Item
3. Item class LAST
4. Item class FIRST
5. Item
[…]

When I add two shortcodes like [etheme_products][etheme_products], the first slider has the classes set like my second example and the second slider has the classes set like the first example.

I really don’t get it, its totally confusing. I would like to ignore all of these confusing classes and just find a way to style the first item of the slider, but I dont know how. :first-child doesnt work here…

Where can I set the slider id? I dont find this option in the slider-settings…

I just need to understand why this part results in these weird classes

// Store loop count we're currently on
if ( empty( $woocommerce_loop['loop'] ) )
	$woocommerce_loop['loop'] = 0;

// Store column count for displaying the grid
if ( empty( $woocommerce_loop['columns'] ) )
	$woocommerce_loop['columns'] = apply_filters( 'loop_shop_columns', 4 );

// Ensure visibility
if ( ! $product || ! $product->is_visible() )
	return;

// Increase loop count
$woocommerce_loop['loop']++;

// Extra post classes
$classes = '';
if ( 0 == ( $woocommerce_loop['loop'] - 1 ) % $woocommerce_loop['columns'] || 1 == $woocommerce_loop['columns'] )
	$classes .= 'first ';
if ( 0 == $woocommerce_loop['loop'] % $woocommerce_loop['columns'] )
	$classes .= 'last ';

I just want the first item in the slider to be marked with “first” or something else, thats all.

Thank you, I did what you said, but the change has no effect, it doesnt add the class.
Here is the code that I added to my childtheme’s functions.php

    function etheme_create_slider($args, $slider_args = array()){//, $title = false, $shop_link = true, $slider_type = false, $items = '[[0, 1], [479,2], [619,2], [768,4],  [1200, 4], [1600, 4]]', $style = 'default'
        global $wpdb, $woocommerce_loop;
        
        $product_per_row = etheme_get_option('prodcuts_per_row');
        extract(shortcode_atts(array( 
	        'title' => false,
	        'shop_link' => false,
	        'slider_type' => false,
	        'items' => '[[0, 1], [479,2], [619,2], [768,4],  [1200, 4], [1600, 4]]',
	        'style' => 'default',
	        'block_id' => false
	    ), $slider_args));

        $box_id = rand(1000,10000);
        $multislides = new WP_Query( $args );
        $shop_url = get_permalink(woocommerce_get_page_id('shop'));
        $class = $container_class = $title_output = '';
        if(!$slider_type) {
        	$woocommerce_loop['lazy-load'] = true;
        	$woocommerce_loop['style'] = $style;
        }
        

        if(!$slider_type) {
            $container_class = '';
            $class .= 'owl-carousel';
        } elseif($slider_type == 'swiper') {
            $container_class = 'et-swiper-container';
            $class .= 'swiper-wrapper';
        }

        if ( $multislides->have_posts() ) :
            if ($title) {
                $title_output = '<h2 class="title"><span>'.$title.'</span></h2>';
            }   
              echo '<div class="carousel-area '.$container_class.' slider-'.$box_id.'">';
                  echo $title_output;
                  echo '<div class="'.$class.' productCarousel">';
                        $_i=0;
                    	if($block_id && $block_id != '' && et_get_block($block_id) != '') {
                            echo '<div class="slide-item '.$slider_type.'-slide">';
                                echo et_get_block($block_id);
                            echo '</div><!-- slide-item -->';
                    	}
                        while ($multislides->have_posts()) : $multislides->the_post();
                            $_i++;
                            $first_slide_class = ( $_i === 1 ) ? 'your-first-slide-class' : '';
                            if(class_exists('Woocommerce')) {
                                global $product;
                                if (!$product->is_visible()) continue; 
                                echo '<div class="slide-item product-slide '.$slider_type.'-slide">';
                                    woocommerce_get_template_part( 'content', 'product-slider' );
                                echo '</div><!-- slide-item -->';
                            }

                        endwhile; 
                  echo '</div><!-- products-slider -->'; 
              echo '</div><!-- slider-container -->'; 
        endif;
        wp_reset_query();
        unset($woocommerce_loop['lazy-load']);
        unset($woocommerce_loop['style']);
        
        if($items != '[[0, 1], [479,2], [619,2], [768,4],  [1200, 4], [1600, 4]]') {
            $items = '[[0, '.$items['phones'].'], [479,'.$items['tablet'].'], [619,'.$items['tablet'].'], [768,'.$items['tablet'].'],  [1200, '.$items['notebook'].'], [1600, '.$items['desktop'].']]';
        } 
        if(!$slider_type) {
	        echo '
	
	            <script type="text/javascript">
	                jQuery(".slider-'.$box_id.' .productCarousel").owlCarousel({
	                    items:4, 
	                    lazyLoad : true,
	                    navigation: true,
	                    navigationText:false,
	                    rewindNav: false,
	                    itemsCustom: '.$items.'
	                });
	
	            </script>
	        ';
        } elseif($slider_type == 'swiper') {
	        echo '
                <script type="text/javascript">
                  if(jQuery(window).width() > 767) {
                      jQuery(".slider-'.$box_id.'").etFullWidth();
                      var mySwiper'.$box_id.' = new Swiper(".slider-'.$box_id.'",{
                        keyboardControl: true,
                        centeredSlides: true,
                        calculateHeight : true,
                        slidesPerView: "auto",
                        mode: "horizontal"
                      })
                  } else {
                      var mySwiper'.$box_id.' = new Swiper(".slider-'.$box_id.'",{
                        calculateHeight : true
                      })
                  }
                
                    jQuery(function($){
                        $(".slider-'.$box_id.' .slide-item").click(function(){
                            mySwiper'.$box_id.'.swipeTo($(this).index());
                            $(".lookbook-index").removeClass("active");
                            $(this).addClass("active");
                        });
                        
                        $(".slider-'.$box_id.' .slide-item a").click(function(e){
                            if($(this).parents(".swiper-slide-active").length < 1) {
                                e.preventDefault();
                            }
                        });
                    }, jQuery);
                </script>
	        ';
        }
            
    }