java - how to update an element from specific index in ArrayList

Question

Closed. This question needs debugging details. It is not currently accepting answers. question from:https://stackoverflow.com/questions/65643986/how-to-update-an-element-from-specific-index-in-arraylist

Answer 1

The type mismatch happens because product.setPurchaseQuantity(pPurchaseQuantity) returns void but productList.set(...) requires an object of type Product as its second argument.

To update the quantity, you need to get a Product from the productList and then operate on the retrieved object. There is no need to set this object again since you are changing an attribute of this object and the reference to it remains in the productList.

Product product = productList.get(productIndex);
product.setPurchaseQuantity(pPurchaseQuantity);