How to store variables in a separate class

Questions & Answers
1

I’m new to Unity and have been coding in Swift for a while. Usually when creating game in Swift I would have a utility class that would exist outside of the game scene. I am trying to implement this in Unity C# and am having all sorts of trouble.

Here is my (simplified) Load script:

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

public class Load : MonoBehaviour {

public GameObject player;
public GameObject goal;
public Util util;

void Start () {
	
	Instantiate(player, new Vector2(0, -4), Quaternion.identity);
	Instantiate(goal, new Vector2(0, 4), Quaternion.identity);

	if (util.level == 0) { // this is line 18
            // do stuff
	}

    }

Here is my (simplified) Utility class:

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

public class Util {

    public int level = 0;

}

I am getting a NullReferenceException: Object reference not set to an instance of an object
Load.Start () (at Assets/Scripts/Load.cs:18)

This is the first time I’m trying to access the utility class. I am thinking that I might need to attach it to a GameObject and call GetComponent each time I want to access it. But this seems very clumsy, is the a way to access the variables using dot syntax? Or is this approach contrary to the way Unity works?

Thanks,
James.

2

It seems like you only want one Util class to exist at any point and to be able to access it anywhere. That’s a static class:

public static class Util
{
     public static int level = 0;
}

With this your load class would become:

public class Load : MonoBehaviour
{
    public GameObject player;
    public GameObject goal;

    void Start()
    {
        Instantiate(/*yada yada*/); 
        Instantiate(/*yada yada*/); 
        if (Util.level == 0){
            //do stuff
        }
    }
}