Accessing a script from another script at runtime in Unity C#

Question

Like in here, but the difference is that it's supposed to be done from an instantiated prefab, so I can not drag the GameObject, that has the script with the variable I want to access, into this script.

This was working

public ScriptA script;

void Update() {
   if (script.varX < 0) {
      // . . .
   }
}

But now I'm getting "Object reference not set to an instance of an object" error, which I think comes from the fact that the script trying to access ScriptA, is attached to an instantiated prefab.

How do I attach scripts and/or GameObjects at runtime?

Answer 1

Looks like you need to find your script type first, if it already exists in the scene:

public ScriptA script;

void Start()
{
    script = GameObject.FindObjectOfType<ScriptA>();
}

void Update()
{
    if(script.variable...)
}