Android game rpg inventory system

Question

I am using an ArrayList as my \"inventory\". I am having trouble figuring out a way to add multiples of the same item without taking up a spot in the \"inventory\". For exam

Answer 1

The usual way to solve this (using the standard API) is to use a Map that maps an item to the number of of such items in the inventory.

To get the "amount" for a certain item, you then just call get:

inventory.get(item)

To add something to the inventory you do

if (!inventory.containsKey(item))
    inventory.put(item, 0);

inventory.put(item, inventory.get(item) + 1);

To remove something from the inventory you could for instance do

if (!inventory.containsKey(item))
    throw new InventoryException("Can't remove something you don't have");

inventory.put(item, inventory.get(item) - 1);

if (inventory.get(item) == 0)
    inventory.remove(item);

This can get messy if you do it in many places, so I would recommend you to encapsulate these methods in an Inventory class.

Good luck!