ItemStack[] - The local variable may not have been initialised yet

Right, excuse this for probably being very simple but I am new the scene and I have exhausted Google, forum search, etc etc

I'm getting the problem where I declare ItemStack[] chest_NOAIR; I get compile errors saying the variable may have not been initialised yet. I've tried relocating it and tried setting it to null but then I get a nullpointerException when I click a chest in-game.

Hope that's enough info, hopefully thanks in advance. =)

Code:

public void onBlockInteract(BlockInteractEvent event){
    System.out.println(event.getBlock().getType());
//    Material chest;

    if (event.getBlock().getTypeId() == 54){
        System.out.println("It's a chest!");
        Chest test = (Chest)event.getBlock().getState();
        CraftChest blockTest = (CraftChest)event.getBlock().getState();
        CraftInventory test2 = (CraftInventory)blockTest.getInventory();
    //    System.out.println(test.getInventory());

        ItemStack[] chest_contents = blockTest.getInventory().getContents();
        System.out.println(chest_contents[0] + "Item at 0");
        System.out.println(chest_contents.length);

        int newItemsStackCount = 0;
        int chest_length = chest_contents.length;
        ItemStack[] chest_NOAIR;
        for (int i = 0; i < chest_length; i++){

            if (chest_contents[i].getTypeId() != 0) {
                chest_NOAIR[newItemsStackCount] = chest_contents[i];
                newItemsStackCount++;
            }
            }
        System.out.println(chest_NOAIR.length);
        }
}

 

That's because you haven't initialised it

Do something like this:

Code:

ItemStack[] chest_NOAIR = new ItemStack[lengthOfArray];

(replacing lengthOfArray with an appropriate number)

 

Thanks for the quick reply!

Does that mean you have to know the length the array will end up at? Eg. If I set that lengthOfArray to 30, I'm going to be outputting a length of 30 every time. I presume that simply using a number above that initialised number doesn't create a new entry in the array?

Edit: Unless I then have to search the array until it becomes a null value? Seems like one too many searches?

Edit2: So I currently have this after it gets all the stuff that's not AIR:

Code:

for (int i = 0; i < chest_NOAIR.length; i++) {
            if (chest_NOAIR[i] != null) System.out.println(chest_NOAIR[i]);

Which as I said works, but is another search...

Edit3: Duh, already found how many spaces in the array get filled up. Replace that < chest_NOAIR.length with the counter I used earlier to put them in the correct cells.

I really should take 5 minutes before I re-edit my post. Though I do find typing something out tends to make me think of a way to fix it. ^^

 

Another solution is to use ArrayLists. They are more dynamic than arrays. They have no defined length. Their length grows and shrinks as your add and remove things from them.