nullException issue [duplicate]

Question

I have a problem when I was trying to change a state within my character. I wrote the code below

 public class playerController : MonoBehaviour {
 private CharacterController characterC;
 private Animator anim;
 // Use this for initialization
 void Start () {
     characterC = GetComponent<CharacterController> ();
     anim = GetComponent<Animator> ();

 }

 // Update is called once per frame
 void Update () {

 }
 // put a line attack!
 public void Attack(){

     anim.SetBool ("attack", true); 
     anim.Play ("attack");
 }
 // when we got a box
 public void Doubleattack(){
     anim.SetBool ("hitBox", true); 
     anim.Play ("doublechop");
 }
 //  dying animation gameover loser
 public void Die(){
     anim.SetBool ("isDead", true); 
     anim.Play ("die");
 }

}

and i use one of my methods in my "mainmanager"

public class MainManeger : MonoBehaviour
{

    private bool isOnlineGame=false;

    private playerController plyC;`

public void start2PlayersGame()
         {
             isOnlineGame = false;
             StartLevel();
             PlayerManeger.set1VS1players();
             AnimationManeger.showGridWindow();
             plyC.Attack ();
             SoundManeger.PlayBackgroudOnPlay();
         }}`

I got this :NullReferenceException: Object reference not set to an instance of an object at ''plyC.Attack ()'' why?

Answer 1

plyC is declared, but not initialized.

I don't know about your exact needs, but maybe you want to add = new playerController() after private playerController plyC. Or maybe Unity's way is to do it in Awake or Start.

Or maybe it exists as a component somewhere else and you have to get it.

In any case, it is not sufficient to only write the line with the type and the variable name, this only creates a null reference, you'll have to assign an instance to it, and that's basically what the error is telling you :)