Object reference not set to an instance of an object

Unity Engine
1

Hello everyone, I’m facing a (apparently) common problem with unity which is this error:
Object reference not set to an instance of an Object C#

However, solutions found here and on the web do not really help me, as most of them is “you havent added component” or other simple things and I have not found anything that simple in my code. So here it is:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class Inventory : MonoBehaviour
{
    public bool[] isFull;
    public GameObject[] slots;
    public Item[] items;
    [SerializeField] ItemSprite itemSprite;

    public void UpdateInventory()
    {
        for (int i = 0; i < isFull.Length; i++)
        {
            if (!isFull[i])
            {
                slots[i].transform.GetChild(0).GetComponent<Image>().sprite = itemSprite.GetSprite(Item.ItemType.Empty);
                Debug.Log("Empty field");
            }
            else
            {
                slots[i].transform.GetChild(0).GetComponent<Image>().sprite = itemSprite.GetSprite(items[i].itemType);
                Debug.Log("Non-empty field");
            }
        }
    }

    void Start()
    {
        items = new Item[isFull.Length];
        for (int i = 0; i < isFull.Length; ++i)
        {
            isFull[i] = false;
            items[i].SetItem(Item.ItemType.Empty, 0);//Object reference not set to an instance of an object
        }

        UpdateInventory();
    }
}

it also uses this code from another file:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Item
{
    public enum ItemType
    {
        Empty,
        BronzeBar,
        SilverBar,
        GoldBar,
        DiamondBar
    }

    public void SetItem(ItemType newItemType, int newAmount)
    {
        itemType = newItemType;
        amount = newAmount;
    }

    public ItemType itemType;
    public int amount;
}

any help will be appreciated!

also hope I haven’t done anything wrong in means of this post, however if I did - please tell me.

2

Yes this is an extremely common error.

First step would be to share your exact error message. Most importantly - the error message will contain a filename, and a line and column number. That will tell us exactly where in your code the error is happening.

3

Some notes on how to fix a NullReferenceException error in Unity3D

  • also known as: Unassigned Reference Exception
  • also known as: Missing Reference Exception

http://plbm.com/?p=221

The basic steps outlined above are:

  • Identify what is null
  • Identify why it is null
  • Fix that.

Expect to see this error a LOT. It’s easily the most common thing to do when working. Learn how to fix it rapidly. It’s easy. See the above link for more tips.

4

Do you ever fill your array “items” ? you define it with a length but you don´t add values ?!

I think you missed something like

items[i] = new Item();

in your for loop.