jQuery closest() vs. find() for Descendant Selection: A Common Mistake and Fix

The problem with the code is that the `closest()` method returns only the first ancestor element that matches the provided selector. So, using `.each()` after `closest()` doesn't make sense because it will iterate over that single matched element only.

If you want to target all elements with the class `.qcart_item` that are descendants of the element with the `item_id`, you can use the `find()` method instead of `closest()`.

Here's the corrected code:

$('#' + item_id).find('.qcart_item').each(function() {
  // Your code here
});

This will find all elements with the class `.qcart_item` that are descendants of the element with the `item_id` and then iterate over each of them using the `each()` method.