How to check/read multiple elements of the same arrayList at the same time in Java?

Question

Im making an rpg game and right now I'm working on crafting. I've made a crafting slot class, and an arrayList of that class. I've got 10 of those slots in total, 9 placed in a 3x3 'order' and 1 below (like the minecraft inventory). I want to check if the 9 slots contain some items in a particular way, and if they do to put a item in the 10th slot. I can figure out how to craft stuff, but I don't know how to read all those 9 slots at the same time (btw Im using an enhanced for loop to update and render all of 'em). I figured I would check if the slots contain items in this order

4 4 4

0 3 0

0 3 0

(4 being stone and 3 being the stick item)

Each slot has its own item variable. So how can I access all of them at the same time? Or even if there is a simpler way to do this. Thank you

Answer 1

You don't need to access them all at once, use a for-loop going from 0 to 8 (1-9 in human counting) to check them against an array of your recipe.