Why am I getting this error?

I am trying to my player shoot. I have all the spawning in place but whenever I try to run this code:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Bullet : MonoBehaviour
6. {
7.     private Rigidbody2D rb;
8.     public float bulletSpeed;
9.     // Update is called once per frame
10.     void Update()
11.     {
12.       rb.velocity = new Vector2(bulletSpeed, rb.velocity.y);
13.     }
14. }
15.  

I get an error saying : NullReferenceException: Object reference not set to an instance of an object
Bullet.Update () (at Assets/Bullet.cs:13). Why am I getting this error?

 

Because Rigidbody2D variable is set as private and you haven't set the reference. Hence the NullReference error. Add a Start or Awake method and do:

rb = GetComponent<Rigidbody2d>();

 

Thanks!