Unity behavior Property not set in inspector, prints null but doesn't == null

Question

I have a property in a MonoBehavior, defined in the following way:

public GameObject whatever = null;

I set it to an actual GameObject reference on some of them, leave it blank in others. Basically, its an optional property. Now, the craziest thing happens when I test it in the program:

Debug.Log(whatever + " " + (whatever == null));

This prints: "null False". I have no idea how to proceed. All I want is to be able to null test it in code. (I have tried removing the = null as well, didn't make a difference). Unity seems to be creating some wrapper or something. Here is a full reduction that reproduces the problem:

using UnityEngine;
using System.Collections;

public class TestBehavior : MonoBehaviour
{
    public GameObject whatever;

    // Use this for initialization
    void Start ()
    {
       Debug.Log("logical: " + whatever + " " + (whatever == null)); // prints null True
       Print(whatever);
    }

    public void Print<T>(T anObject)
    {
       Debug.Log("Now it gets nuts: " + anObject + " " + (anObject == null)); // prints null False
    }
}

`null` gets treated like an empty-string during concatenations, so it should be outputting " false".. — BlueRaja - Danny Pflughoeft, Feb 06 '14 at 23:35
Also you shouldn't be comparing generic parameters to `null`, see http://stackoverflow.com/a/864860/238419 . Though, that still should not cause the issue you're seeing.. — BlueRaja - Danny Pflughoeft, Feb 06 '14 at 23:41

score 0 · Answer 1 · answered Feb 06 '14 at 23:14

I have experienced similar behaviour when attempting to instantiate a Behaviour in Unity - there are some things ill understood going on under the hood.

A quick fix for this might be to refer to a specific Script instead of the entire Game Object - especially since most things you need to cross access are contained in another script (HP, for example) or are just as accessible (transform, characterController) if whatever is a MonoBehaviour

Unity behavior Property not set in inspector, prints null but doesn't == null

1 Answers1