jQuery: How to Iterate Over Children of Closest Element

The problem with the code is that the 'closest' method returns a single element, not a collection of elements. Therefore, there is no need to use the 'each' function afterwards.

To achieve the desired result, you can modify the code as follows:

$('#'+item_id).closest('.qcart_item').find('.qq_item_data').each(function() {
    // code to be executed for each qq_item_data element
});

In this code, $('#'+item_id) selects the element with the specified item_id, closest('.qcart_item') finds the closest ancestor element with the class 'qcart_item', and find('.qq_item_data') selects all descendant elements with the class 'qq_item_data'. The 'each' function then iterates over each of these elements.