Adding GameObject to list causes crash

Unity Engine
1

Hi, I’m having some problem with a part of a code I’m currently writing in C#.

See, I have this list

private List<GameObject> selectedPlanetNodes;

And I want to add a GameObject to it during this method

void SetStartingPlanet()
    {
        // Get random number between 0 < number of planets
        int randomNumber = Random.Range(0, planetNodeList.Count - 1);
        Debug.Log(planetNodeList.Count);

        // Set nodes to planet of random number  Set starting planet to selected
        m_currStartNode = planetNodeList[randomNumber];
        

        m_prevSelectNode = m_currStartNode;

        Debug.Log(m_currStartNode.name);
        Debug.Log(m_currStartNode.gameObject);
        //Debug.Log(selectedPlanetNodes.Capacity);
        //Debug.Log(selectedPlanetNodes.Count);

        selectedPlanetNodes.Add(m_prevSelectNode); <----- [B][COLOR="#FF0000"]ERROR OCCURS HERE!![/COLOR][/B]

        m_currStartNode.GetComponent<script_PlanetNode>().IsSelected = true;

        // Set random goal planet
        do
        {
            SetGoalPlanet();
        } while (m_currGoalNode == m_currStartNode);
    }

The SetStartingPlanet() method is called in the start method. Now, the problem I’m facing is that when I try to run the code I get a error saying NullReferenceException: Object reference not set to an instance of an object. I have tried a million things and I can’t get it to work. Even weirder is that when I made sure to initialize the list in the start () method (using selectedPlanetNodes = new List(); ), the only thing that happened was that now Unity crashes every time i run the scene.

Would be thankful for any help.

2

The new approach is correct. Make sure that you don’t have an infinite loop at the end of the method.

3

Are you creating your list anywhere? because im not see it.

selectedPlanetNodes = new List();

4

Aha, thanks! =) Seems like the do-while loop was infinite. I thought it would go inside and set the m_currGoalPlanet without having to set the variable before the loop (it was set to null before).