Roll a Ball game - NullReference Exception

Questions & Answers
1

I started with the Build a Ball tutorials, but am stuck on tutorial 7, “Displaying Score and Text”. The program runs, but the score stays at 0 when the “Player” hits the “Pick Ups”. The error that I am getting is NullReference Exception: Object reference not set to an instance of an object PlayerControl.Start() (at Assesst/Scripts/PlayerControl.cs: 21.

I check the program with the printout of the tutorial code and all of the variables. Does someone have a working game I could look at? Or if you had this problem, how did you fix it?

2

public Text winText; // Hello, I am null!!!
winText is null. you need to assign it in the inspector.

Alternatively, make the code work without winText assigned.

using UnityEngine;
using UnityEngine.UI;

public class PlayerControl : MonoBehaviour
{
    public float speed;
    public Text countText;
    public Text winText;

    private Rigidbody rb;
    private int count;

    void Start()
    {
        rb = GetComponent<Rigidbody>();
        WarnMissingReference(countText, "Count Text");
        WarnMissingReference(winText, "Win Text");
        UpdateText();
    }

    void FixedUpdate()
    {
        float moveHorizontal = Input.GetAxis("Horizontal");
        float moveVerticle = Input.GetAxis("Vertical");
        Vector3 movement = new Vector3(moveHorizontal, 0.0f, moveVerticle);
        rb.AddForce(movement * speed);
    }

    void OnTriggerEnter(Collider other)
    {
        if (other.gameObject.CompareTag("Pick Up"))
        {
            other.gameObject.SetActive(false);
            ++count;
            UpdateText();
        }
    }

    void UpdateText()
    {
        bool win = count >= 8;
        SetText(winText, win ? "You Win!" : "");
        SetText(countText, "Count: " + count);
    }

    void SetText(Text obj, string text)
    {
        if (obj)
            obj.text = text;
    }

    void WarnMissingReference(Object obj, string name)
    {
        if (!obj)
            Debug.LogWarningFormat(this, "{0} has not been assigned", name);
    }
}