Object reference not set to an instance of object with Inheritance

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Object reference not set to an instance of object with Inheritance

godotMonoNoob

In my GhostScript I have:

public class GhostScript
{
   protected Timer patrolTimer;

   public override void _Ready()
   {
        patrolTimer = GetNode<Timer>("PatrolTimer");
   }
}

And then in my BlueGhost script I have:

public class BlueGhostScript : GhostScript 
{
   public BlueGhostScript()
   {
     patrolTimer.Paused = true; 
   }
}

Why does this result in "Object reference not set to an instance of object error?"
If I replace it with GetNode<Timer>("PatrolTimer").Paused = true;, it does work, but why does patrolTimer.Paused = true not work? I already got the reference to the node in the GhostScript didn't I?

Kojack

_Ready isn't called when you instantiate a class, it happens later when the object enters the scene tree.
So when your BlueGhostScript constructor is called, the GhostScript's _Ready hasn't been called yet and therefore patrolTimer is null.

godotMonoNoob

The way I fixed the issue was by putting it in the ready of blueghostscript with base.ready so that the reference to the timer that ghostscript got was carried over into blueghostscript

public class BlueGhostScript : GhostScript 
{
   public override void _Ready()
   {
       base._Ready();
       patrolTimer.Paused = false;
   }
}