How to pull a variable from a separate C# script.

Question

I am trying to pull a variable from another script within Unity using C#. I am building a game in which I need to reference a specific script depending on the location of objects in the scene. This variable has a constant value but this value will change from script to script. However, there seems to be an error with our code below, it will not recognize any of our GetComponet statements and we cannot pull any variables from that script into the main script. I can be more specific if the information provided is insufficient. Thank you!

 using UnityEngine;
 using System.Collections;
 
 public class Base : MonoBehaviour {
     string team = "neutral";
     public bool cpt = true;
 
     void Start () {
     
     }
     
     void Update () {
     
     }
 }

The variable pulled from this script will be the Boolean cpt and will be referenced here:

 using UnityEngine;
 using System.Collections;
 
 public class EntityMove : MonoBehaviour {
 
     private Vector3 cursorPosition;
     private Vector3 entityPosition; 
     private bool cpt = false;
 
     void Start () {
 
         GameObject.Find("cursor").GetComponent<menuAll> ().enabled = false;
     }
 
     void Update () {
         cursorPosition = GameObject.Find("cursor").transform.position;
         entityPosition = transform.position;
 
         float dist = Vector3.Distance (entityPosition, cursorPosition);
         if ((dist == 0) && Input.GetButtonDown ("Select") ) {
             print ("It works");
 
 //reference cpt in the following conditional statement
 
             if (cpt == true) {
                 GameObject.Find ("cursor").GetComponent<menuAll> ().enabled = true;
                 GameObject.Find ("cursor").GetComponent<CursorMove> ().enabled = false;
             }
         }
     }
 }

Answer 1

First of all, you should really educate yourself into writing proper c# code.

To use variables (Fields) from other components (MonoBehaviour), your variables should be marked internal or public (this is correct in your case). However you should understand the concept when using other object's variables, you should have access to the object of where the variable is coming from.

In your example (if I'm correct) you would like to use the "cpt" variable from the "Base" class inside your "EntityMove" class. In order to achieve this your code should look as follow (I corrected some C# ugliness if you don't mind):

 public class Base : MonoBehaviour
     { 
         public bool Cpt = true;
         private string team = "neutral";
 
         protected void Start()
         {
 
         }
 
         protected void Update()
         {
 
         }
     }
 
     public class EntityMove : MonoBehaviour
     {
         private Vector3 cursorPosition;
         private Vector3 entityPosition;
         private Base baseClass;
         private GameObject cursor;
         private menuAll menuAll; // Please start public classnames with a Capital letter! (menuAll => MenuAll)
         private CursorMove cursorMove;
 
         protected void Start()
         {
             baseClass = FindObjectOfType<Base>();
             // Please don't use string based find queries but try to use FindObjectOfType<T>() of even better GetComponent<T>()
             // This is safer and faster
             cursor = GameObject.Find("cursor");
             menuAll = cursor.GetComponent<menuAll>();
             cursorMove = cursor.GetComponent<CursorMove>();
             menuAll.enabled = false;
         }
 
         protected void Update()
         {
             cursorPosition = cursor.transform.position;
             entityPosition = transform.position;
 
             float dist = Vector3.Distance(entityPosition, cursorPosition);
             if ((dist == 0) && Input.GetButtonDown("Select"))
             {
                 print("It works");
 
                 if (baseClass.Cpt)
                 {
                     menuAll.enabled = true;
                     cursorMove.enabled = false;
                 }
             }
         }
     }

However what I think that you actually want to do is to let the class "EntityMove" inherit from "Base". This requires a bit more C# knowledge about inheritance, but should look like this:

 public class Base : MonoBehaviour
     { 
         protected bool Cpt = true;
         protected string team = "neutral";
 
         protected void Start()
         {
 
         }
 
         protected void Update()
         {
 
         }
     }
 
     public class EntityMove : Base
     {
         private Vector3 cursorPosition;
         private Vector3 entityPosition;
         private GameObject cursor;
         private menuAll menuAll; // Please start public classnames with a Capital letter! (menuAll => MenuAll)
         private CursorMove cursorMove;
 
         protected void Start()
         {
             // Please don't use string based find queries but try to use FindObjectOfType<T>() of even better GetComponent<T>()
             // This is safer and faster
             cursor = GameObject.Find("cursor");
             menuAll = cursor.GetComponent<menuAll>();
             cursorMove = cursor.GetComponent<CursorMove>();
             menuAll.enabled = false;
         }
 
         protected void Update()
         {
             cursorPosition = cursor.transform.position;
             entityPosition = transform.position;
 
             float dist = Vector3.Distance(entityPosition, cursorPosition);
             if ((dist == 0) && Input.GetButtonDown("Select"))
             {
                 print("It works");
 
                 if (Cpt)
                 {
                     menuAll.enabled = true;
                     cursorMove.enabled = false;
                 }
             }
         }
     }

Good luck on your coding adventure and try to do some C# tutorials to learn more in depth C# and .NET knowledge.

How to pull a variable from a separate C# script.

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