• Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
  • Asset Store
  • Get Unity

UNITY ACCOUNT

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account
  • Blog
  • Forums
  • Answers
  • Evangelists
  • User Groups
  • Beta Program
  • Advisory Panel

Navigation

  • Home
  • Products
  • Solutions
  • Made with Unity
  • Learning
  • Support & Services
  • Community
    • Blog
    • Forums
    • Answers
    • Evangelists
    • User Groups
    • Beta Program
    • Advisory Panel

Unity account

You need a Unity Account to shop in the Online and Asset Stores, participate in the Unity Community and manage your license portfolio. Login Create account

Language

  • Chinese
  • Spanish
  • Japanese
  • Korean
  • Portuguese
  • Ask a question
  • Spaces
    • Default
    • Help Room
    • META
    • Moderators
    • Topics
    • Questions
    • Users
    • Badges
  • Home /
avatar image
0
Question by Jab2565 · Aug 19, 2013 at 07:40 PM · getcomponentnull referance exeption

Null Reference Exception Issue with GetComponent()

I've been trying to get getcomponent to work with getting an enemyobject to take a variable from another script on an empty object titled GameController. The enemy object is a prefab while the GameController is not. I'm getting the Null Reference Exception problem when trying to get the speed variable from the gamecontroller and I don't know what the problem is.

Here is the enemybehavior script:

 private var newEnemySpeed:GameController;  
 private var enemySpeed: float;
 
 function Start () {
 newEnemySpeed.GetComponent(GameController);
 enemySpeed= newEnemySpeed.enemySpeed;
 }
 
 function Update () {
 
 Move(enemySpeed);
 }
 
 function Move(a:float)
 
 {
     
     
     transform.Translate(Vector3.left * a * Time.deltaTime);
     if (transform.position.x <= -12)
         {
         Destroy(gameObject);
         }
 }

on the GameController object is a variable: enemySpeed that will increase in value every second.

Comment
Add comment · Show 2
10 |3000 characters needed characters left characters exceeded
▼
  • Viewable by all users
  • Viewable by moderators
  • Viewable by moderators and the original poster
  • Advanced visibility
Viewable by all users
avatar image Graham-Dunnett ♦♦ · Aug 19, 2013 at 07:46 PM 0
Share

GetComponent usually works on a GameObject, so I'd expect your newEnemySpeed to be a GameObject. How does this variable get initialised? In your code it's never given a value.

avatar image Jab2565 · Aug 19, 2013 at 07:48 PM 0
Share

I don't think it's getting initialized anywhere else as it's set to a private variable so it's not showing up on the inspector.

1 Reply

· Add your reply
  • Sort: 
avatar image
1
Best Answer

Answer by meat5000 · Aug 19, 2013 at 07:54 PM

I think this line doesnt do anything :

 newEnemySpeed.GetComponent(GameController);

I could be wrong :/ but you probably need to make it equal something

 newEnemySpeed = GameController.GetComponent(GameController);

which is :

 newEnemySpeed{script] = GameController[GameObject].GetComponent(GameController[Script]);
Comment
Add comment · Show 1 · Share
10 |3000 characters needed characters left characters exceeded
▼
  • Viewable by all users
  • Viewable by moderators
  • Viewable by moderators and the original poster
  • Advanced visibility
Viewable by all users
avatar image Jab2565 · Aug 20, 2013 at 01:09 AM 0
Share

I was following the logic from the tutorial on getcomponent and I thought that one script can access the variables of a script via getcomponent.

Your answer

Hint: You can notify a user about this post by typing @username

Up to 2 attachments (including images) can be used with a maximum of 524.3 kB each and 1.0 MB total.

Welcome to Unity Answers

If you’re new to Unity Answers, please check our User Guide to help you navigate through our website and refer to our FAQ for more information.

Before posting, make sure to check out our Knowledge Base for commonly asked Unity questions.

Check our Moderator Guidelines if you’re a new moderator and want to work together in an effort to improve Unity Answers and support our users.

Follow this Question

Answers Answers and Comments

17 People are following this question.

avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image avatar image

Related Questions

Problem calling variable across scripts (Closed) 1 Answer

Running a script function using "GetComponent" 1 Answer

Custom _GetComponent( ) 2 Answers

NullReferenceException when setting Component as Variable, but no bugs 1 Answer

Getting all scripts attached to a gameObject (Problem) 1 Answer


Enterprise
Social Q&A

Social
Subscribe on YouTube social-youtube Follow on LinkedIn social-linkedin Follow on Twitter social-twitter Follow on Facebook social-facebook Follow on Instagram social-instagram

Footer

  • Purchase
    • Products
    • Subscription
    • Asset Store
    • Unity Gear
    • Resellers
  • Education
    • Students
    • Educators
    • Certification
    • Learn
    • Center of Excellence
  • Download
    • Unity
    • Beta Program
  • Unity Labs
    • Labs
    • Publications
  • Resources
    • Learn platform
    • Community
    • Documentation
    • Unity QA
    • FAQ
    • Services Status
    • Connect
  • About Unity
    • About Us
    • Blog
    • Events
    • Careers
    • Contact
    • Press
    • Partners
    • Affiliates
    • Security
Copyright © 2020 Unity Technologies
  • Legal
  • Privacy Policy
  • Cookies
  • Do Not Sell My Personal Information
  • Cookies Settings
"Unity", Unity logos, and other Unity trademarks are trademarks or registered trademarks of Unity Technologies or its affiliates in the U.S. and elsewhere (more info here). Other names or brands are trademarks of their respective owners.
  • Anonymous
  • Sign in
  • Create
  • Ask a question
  • Spaces
  • Default
  • Help Room
  • META
  • Moderators
  • Explore
  • Topics
  • Questions
  • Users
  • Badges