Does unity alter the C# definition of "this"?

Condensing it down to the basic problem, I have the script for my Tower class applied to an empty GameObject called "contains crap". This was just to get it into the game so that I can test its behaviour.

 using UnityEngine;
 using System.Collections;   
 
 public class Tower : Segment {
     
     void Start () {
     
         battlements = new Battlements(this);
         battlements.initialise();
     
     }
     
 }

And then the battlements class contains:

 using UnityEngine;
 using System.Collections;
 
 
 public class Battlements : Component {
     public Segment owner;
     private $$anonymous$$achinolation machinolation;
 
 
     //constructor
     public Battlements(Segment dad)
     {
         owner = dad;
 
     }
 
     // -------------------------------Initialise function
     public void initialise()
     {
         Debug.Log (owner);
 // log says "Contains Crap (Tower)"
         Debug.Log (this);
 //log says "null"
 
 machinolation = new $$anonymous$$achinolation (this);
         machinolation.initialise ();
 
     }
 }

Note that "this" seemers to return "null". The real problem ofcourse, is that any reference to the passed component in the machinolations class results in a null reference exception.

Please try adding a "`Debug.Log(battlements);`" line at the end of Tower.Start().

I think that what we are finding is that unity is detecting that this instance of Battlements is an invalid Component ("A component is always attached to a game object.") and casting it to null during a type cast.

That line causes as error:

Assets/scripts/Components/Battlements.cs(29,27): error CS0119: Expression denotes a type', where a variable', value' or method group' was expected

Is the problem that Component is a reserved word? I defined my own class "Component" as the base class for the Battlements class:

 using UnityEngine;
 using System.Collections;
 
 public class Component : Object {
 
     public Segment owner;
 // desclares some other variables
     
     public void initialiseGenerics()
     {
 
         // does some stuff
 
     }
 
     public virtual void initialise(){ }
 
     
 
     public void bump(Tweak tweaked) {
         //do stuff
     }
 }
 
     

I think you must have misunderstood what I was saying but is doesn't matter, I was discussing your Battlements being a descendant of Component but the issue can be explored in simpler terms.

If you run the this class against the following alternative "test" classes you will see different results:

Run$$anonymous$$e

 using UnityEngine;
 using System.Collections;
 
 public class Run$$anonymous$$e : $$anonymous$$onoBehaviour {
     void Start () {
          Test test = new Test();
         Debug.Log("test equals null: " + (test == null));
         Debug.Log("test ToString: " + test);
     }
 }

Test #1

 using UnityEngine;
 using System.Collections;

 // inherits from System.Object    
 public class Test {  
 }
 //Output:
 //test equals null: False
 //test ToString: Test

Test #2

 using UnityEngine;
 using System.Collections;

 // inherits from UnityEngine.Object
 public class Test: Object { 
 }
 //Output:
 //test equals null: True
 //test ToString: null

Test #3

 using UnityEngine;
 using System.Collections;

 // inherits from UnityEngine.Object
 public class Test: Object {  
     override public string ToString() {
         return "I'm real";
     }
 }
 //Output:
 //test equals null: True
 //test ToString: I'm real

So as your Battlements class above is a descendant of Unity's Object it was likely being cast to null as part of the Debug.Log(). What I would like to know now is what is required to pass the "`== null`" test?

So in the machicolation object, here is the first place it has a runtime null reference exception:

"if (owner.owner.maxFloor > 0){"

There would of course be a dozen other null reference exceptions past this point. And the Battlements object has no problem referring to this property as: "owner.maxFloor"