NullReferenceException when trying to find Object

Unity Engine
, ,
1

Hello everyone,

I have this problem where this code leads to a NullReferenceException, i am new to coding in Unity, but im guessing that it isnt finding the Gameobject even tho I do have one with the exact same name. I dont know how to fix this.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Enemy : MonoBehaviour
{

    public int health;
    public Transform target;
    public float speed = 3f;
    public float rotateSpeed = 0.0025f;
    private Rigidbody2D rb;


    public void TakeDamage(int damage)
    {
        health -= damage;

        if (health <= 0)
        {
            Die();
        }
    }

    void Die()
    {
        Destroy(gameObject);
    }

    private void Start()
    {
        rb = GetComponent<Rigidbody2D>();
    }

    private void Update()
    {
        if (!target)
        {
            GetTarget();
        }
        else
        {
            RotateTowardsTarget();
        }

    }

    private void FixedUpdate()
    {
        //Move Forwards
    }


    private void RotateTowardsTarget()
    {
        Vector2 targetDirection = target.position - transform.position;
        float angle = Mathf.Atan2(targetDirection.y, targetDirection.x) * Mathf.Rad2Deg - 90f;
        Quaternion q = Quaternion.Euler(new Vector3(0, 0, angle));
        transform.localRotation = Quaternion.Slerp(transform.localRotation, q, rotateSpeed);
    }


    private void GetTarget()
    {
        Debug.Log(target);
        target = GameObject.FindGameObjectWithTag("Player").transform;
        
    }
}

The problem occurs on the target = GameObject.FindGameObjectWithTag("Player").transform; .

2

The answer is always the same… ALWAYS!

How to fix a NullReferenceException error

Three steps to success:

  • Identify what is null ← any other action taken before this step is WASTED TIME
  • Identify why it is null
  • Fix that

NullReference is the single most common error while programming. Fixing it is always the same.

Some notes on how to fix a NullReferenceException error in Unity3D:

http://plbm.com/?p=221

In your case above, line 66 is too long and tries to do too much.

You need to check if you found the player before you attempt to use the transform.

If you have more than one or two dots (.) in a single statement, you’re just being mean to yourself.

Putting lots of code on one line DOES NOT make it any faster. That’s not how compiled code works.

The longer your lines of code are, the harder they will be for you to understand them.

How to break down hairy lines of code:

http://plbm.com/?p=248

Break it up, practice social distancing in your code, one thing per line please.

“Programming is hard enough without making it harder for ourselves.” - angrypenguin on Unity3D forums

“Combining a bunch of stuff into one line always feels satisfying, but it’s always a PITA to debug.” - StarManta on the Unity3D forums