Object reference not set to an instance of an object

Unity Engine
1

Hello everyone,

I have looked for similar errors that other have been getting and I could not find one that was similar.

Here is my problem simplified…

I have two objects and two scripts. That need to interact with one another, for example, Object A is for scoring or something along that line. Object B will increment a variable on Object A.

Here is some simplified code from each script.

ScriptA

using UnityEngine;
using System.Collections;

public class ScriptA : MonoBehaviour {

    public int x;
    public GUIText xUI;

    void Awake(){
        x = 50;
    }

    void Update(){
        xUI.text = "X = " + x.ToString ();
    }
}

ScriptB

using UnityEngine;
using System.Collections;

public class ScriptB : MonoBehaviour {

    public ScriptA otherScript;
    public bool incrementX;

    void Awake(){
        incrementX = false;
    }

    void increment_X(){
        otherScript.x += 50;
    }

    void Update (){
        if (incrementX == true)
            increment_X ();
    }
}

2034273--131797--1.png
2034273--131797--1.png669×579 75.8 KB

Here is my question.

I know that I can easily just drag Object A into the location in Object B within the Inspector, however, Object B is going to be instantiated multiple times in random location around a map from it’s prefab location within the assets folder. I am trying to figure out how to get Object B to recognize Object A upon being spawned.

Some of the solutions that I have tried are using

GetComponents - within the Awake function - otherScript = GetComponent();
This did not work.

GameObject.Find - within the Awake function - otherScript = GameObject.Find (“Object A”);
This gave an error of - Cannot implicitly convert type UnityEngine.GameObject' to ScriptA’ - which makes sense.

Could someone help me with a solution or point me at material that I could look over to hopefully fix this solution.

Thanks

Nic

2

You’re on the right track. Find the game object first then get the component.

GameObject objectA = GameObject.Find("Object A");
ScriptA scriptA = objectA.GetComponent<ScriptA>();
3

Or create a Manager script which holds a reference to ObjectA and the prefab with ObjectB to be instantiated. Then within this manager, whenver you instantiate an ObjectB, give it a reference to ObjectA.

1 Like
4

Thank you guys for your response and help!