if class qq_product_multi_slide exist in page do flickticky in jquery

You can achieve this using the jQuery hasClass() method and the slick() method. Here's an example of how you can implement it:

if ($('.qq_product_multi_slide').length) {
  // If the element with class .qq_product_multi_slide exists on the page
  $('.qq_product_multi_slide').slick();
}

Explanation:

1. $('.qq_product_multi_slide').length checks if any element with class .qq_product_multi_slide exists on the page.
2. If it exists, the slick() method is called on the element to activate the flickticky behavior (assuming you have included the slick carousel library).

Make sure you have also included the jQuery library and the slick carousel library in your HTML file before using this code