Accessing variable defined in a Script attached to Prefab

GameObject.GetComponent

I tried doing this

 var elementInfo:ElementInfo;
 function Start () 
 {
     elementInfo=FindObjectOfType(typeof(ElementInfo));
 }
 function Update () 
 {
     print(elementInfo.Element.ToString());
 }

But it shows

   NullReferenceException: Object reference not set to an instance of an object
     TestScriptForJson.Update () (at Assets/ReactionScreenScript/TestScriptForJson.js:30)

can you point out what is the problem. I have been using this method successfully for accessing variables of other scripts. And just one more question for understanding purpose. Since there are multiple instances of prefab so when accessing the variable how will it come to know which element it is accessing or it will take information from all the instances.

That's not how your properly get components from other game objects. FindObjectOfType of used to find game objects, not to get a component. That's what GetComponent is there for. Get the component, make sure it's not null and then use it to fetch any variable you want.

As per your query on whether FindObjectOfType gets the first or all instances, from this link: "Returns the first active loaded object of Type type. Please note that this function is very slow. It is not recommended to use this function every frame. In most cases you can use the singleton pattern ins$$anonymous$$d."

FindObjectOfType returns the first one
FindObjectsOfType returns a list

Glad you go it sorted out! Convert your last comment to an answer and accept it to close this question :)

Just got one more thought regarding FindObjectOfType and FindObjectsOfType you guys said that FindObjectOfType will fetch me only the first active instance of that script. So If am looking to access the script which is attached to a prefab it will get me just the first instance of the script and not the others. ?

Again, you're still confusing between 'finding an object' and 'getting a component/script from an object' - FindObjectOfType will search the whole scene and once it finds the first active object of the type you specify it will return it to you. While if you had a game object and wanna get a component from it, you should do gameObject.GetComponent

Ohkkk got it. Sorry for all the confusion i am quite new to unity and trying to learn as much as i can and get confuse in the end.

I strongly suggest you try to avoid all those FindObject variations. In some cases you have no choice, and this is a good option, but you should familiarize yourself with other mechanisms for obtaining a reference to an object. I have developed two full games now, and never used FindObjectOfType or its array returning brother.

Using it for scripts and not for GameObjects. $$anonymous$$ay be somewhere made some mistake but since its working with this would stick to them and get done with the application.And may be later change it after releasing beta version of the application.Thanks for your helps its nice to get help from experienced persons like you..! If Can you check this link and provide your valuable suggestion on this application which am working on as of now.!

Doing something in a way that 'works' doesn't necessarily mean that's the best way to do it. You should always seek to learn the best habit of doing something. If you learn a wrong habit it will stick with you and the quality of your apps will degrade. And the best way to learn good habits, is to learn from those of higher experience. UnityGems is a good place to learn with high quality - Also, I advice you to learn C#, it has a lot of powerful features, check this out.

True.. its not the right way but then its better to launch a beta version first and then work on this bad aspect later and make it better for user.And I will definitely learn from the UnityGems. As of now i am sticking to Unity Script as am comfortable with it though will learn C# side by side. Learning new tricks is always good and always eager to learn them.