title: Set item quantity to multiples of “x” for products in a specific different categories in WooCommerce
body: <p>I am trying to display an alert message on the cart page of my web site managing 2 different quantity multiples for 2 different categories.</p>
  <p>Categories are:</p>
  <ul>
  <li>Birre 33 cL (slug: birre-33-cl ID:187) for Multiple quantities of 6</li>
  <li>Birre 75 cL (slug: birre-75-cl ID:188) for Multiple quantities of 12</li>
  </ul>
  <p>I need to count and manage them separately (you can buy 12/24/36... bottles of 33 cL and 6/12/18... bottles of 75 cL, but not 6 bottles of 33 cL and 6 bottle of 75 cL).</p>
  <p>I have modified <a href="https://stackoverflow.com/questions/52612495/set-item-quantity-to-multiples-of-x-for-products-in-a-specific-category-in-woo/52612956#52612956">this code</a> to suit my needs:</p>
  <pre><code>//FILL THE BOX BIRRE 33 CL
  function has_product_category( $product_id, $category_ids ) {
      $term_ids = array(); 
  
      // Loop through the current product category terms to get only parent main category term
      foreach( get_the_terms( $product_id, 'product_cat' ) as $term ){
          if( $term-&gt;parent &gt; 0 ){
              $term_ids[] = $term-&gt;parent; // Set the parent product category
              $term_ids[] = $term-&gt;term_id;
          } else {
              $term_ids[] = $term-&gt;term_id;
          }
      }
      return array_intersect( $category_ids, array_unique($term_ids) );
  }
  
  add_action( 'woocommerce_check_cart_items', 'woocommerce_check_cart_quantities' );
  function woocommerce_check_cart_quantities() {
      $multiples = 12;
      $total_products = 0;
      $category_ids = array( 187 );
      $found = false;
  
      foreach ( WC()-&gt;cart-&gt;get_cart() as $cart_item ) {
          if ( has_product_category( $cart_item['product_id'], $category_ids ) ) {
              $total_products += $cart_item['quantity'];
              $found = true;
          }
      }
      if ( ( $total_products % $multiples ) &gt; 0 &amp;&amp; $found )
          wc_add_notice( sprintf( __('FILL YOUR 33 cL BOX: you have to buy multiples of %s.', 'woocommerce', 'woocommerce'), $multiples ), 'error' );
  }
  </code></pre>
  <p>Unfortunately I am not able to manage to 2 different categories with different displayed message for each.</p>
  <p>Any help is appreciated.</p>