Object Reference not set to an instance of an object

Unity Engine
1 
using UnityEngine;
using System.Collections;

public class gridManager : MonoBehaviour {

	bool blahblah = false;

	public GameObject[,] world;

	public void addToWorld (int x, int y, string type){
		//if the array position is not empty
		if (world [x,y] != null) {
			GameObject n = (GameObject)Instantiate(Resources.Load(type));
			//tell the object where is is
			n.transform.position = new Vector2(x*10,y*10);
			world [x,y] = n;
		}
	}

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
		if (blahblah == false) {
			addToWorld (2,2,"Test Object");
			blahblah = true;
		}
	
	}
}

I assume its not finding the “Test Object” prefab?

What I’m trying to do is Instantiate a prefab with ‘guidance’ from a grid manager. For now I’m trying to check if the array position is empty. If it is, instantiate the “Test Object” prefab at the given x,y coords (*10, because grid size ofc.) Then put a reference to the game object in the array so I can check if from other objects later, by position in the array (and by extension in the game world.)

Any help would be great.

Halbera.

EDIT:

NullReferenceException: Object reference not set to an instance of an object
gridManager.addToWorld (Int32 x, Int32 y, System.String type) (at Assets/gridManager.cs:12)
gridManager.Update () (at Assets/gridManager.cs:28)
2

The full error (particularly the line number) would help. These types of errors are also abstract, but it may help.

Also, not the best at C#, but in line 8, shouldn’t it be GameObject[0] rather than [,]?

And, sorry that my mind isn’t really able to understand that code at the moment. Good luck!

3

I’m trying to make a 2 dimensional array, I read in the scripting docs that is done using [,]

Thanks anyway.