NullReference exception problem

Questions & Answers
1

Hi

I have the following code which produced the error “NullReferenceException: Object reference not set to an instance of an object” at the line where I try to enqueue one of the linkedDialogues but I’m not sure why I am getting the error because if I log the object I seem to be able to access it. The Dialogues extend ScriptableObject. I’m not sure if this is the problem. Any ideas anyone?

float currentPosX = 20.0f;
        Queue<Dialogue> queue = new Queue<Dialogue>();
        queue.Enqueue(workingSequence.RootDialogue);

        while(queue.Count > 0)
        {
            Dialogue currentDialogue = queue.Dequeue();
            if(currentDialogue == null)
            {
                Debug.Log("null");
                continue;
            }

            for (int index = 0; index < currentDialogue.linkedDialogues.Count; index++ )
            {
                if (currentDialogue.linkedDialogues[index] != null)
                {
                    Debug.Log(currentDialogue.linkedDialogues[index].name);
                   //ERROR IN THIS LINE BUT CAN ACCESS OBJECT WITH ABOVE LOG STATEMENT 
                   queue.Enqueue(currentDialogue.linkedDialogues[index]);
                }
            }

            nodes.Add(new DialogueNode(currentDialogue, this, nodes.Count + 1, new Rect(currentPosX, 20, 400, 0)));
            currentPosX += 200.0f;
        }
2

Won’t

for(int index = 0; index < currentDialogue.linkedDialogues.Count; index++ )

go beyond your index by one (because of 0-indexing)?

for(int index = 0; index < currentDialogue.linkedDialogues.Count-1; index++ )

instead.