[Beginner] Why can't you use Find to declare a variable in the main class?

Code (csharp):

1.  
2. using UnityEngine;
3. using System.Collections;
4.  
5. public class FollowPlayer : MonoBehaviour {
6.  
7.     GameObject plr = GameObject.Find("Player");
8.     public Vector3 offset;
9.  
10.     void Update()
11.     {
12.         transform.position = plr.transform.position + offset;
13.     }
14.  
15. }
16.  
17.  

I saw that using Find in an Update is a big no no because it's slow and I don't want to make the habit, but I'm not sure how to go about creating a reference outside of the Update function without doing this.

 

You should use Find in either Start or Awake if you plan to use it, but the better way is just declare a public GameObject variable and drag and drop in the inspector.

 

Why you can't do that is described in the "Calling Unity API from constructor/field initializers" paragraph:
https://blogs.unity3d.com/2016/06/06/serialization-monobehaviour-constructors-and-unity-5-4/

 

That's the way I thought it should be too! In the tutorial I am watching, the instructor said that method of doing it is alright but if the object is removed from the scene and added back or something like that, the drag and drop references will be lost. The way he said it made me think that drag and drop references shouldn't typically be used.

 

Drag and drop is the preferred method. I don't know much about your instructor, but no matter how you set things up, if a gameobject is removed, you lose the reference anyways, so that doesn't really change how you set the initial part up.

If you expect to remove something from the scene, you have to handle the references properly. Checking for null, changing what your variables point to, whatever is needed for your game.