# get a variable through GetComponent
**URL:** https://discussions.unity.com/t/get-a-variable-through-getcomponent/86578
**Category:** Questions & Answers
**Created:** [November 13, 2013, 2:04am UTC](https://discussions.unity.com/t/get-a-variable-through-getcomponent/86578 "2013-11-13T02:04:30Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@thenachotech1113](https://discussions.unity.com/u/thenachotech1113)
#### Post date: [November 13, 2013, 2:04am UTC](https://discussions.unity.com/t/get-a-variable-through-getcomponent/86578/1 "2013-11-13T02:04:30Z")
hey everyone, my problem is the following: i want several scripts to have a variable that has the same value in every script, and if the variable changes in game i need them all to change. looking for a way to do this i stumbled upon SendMessage and GetComponent. The option that was aparentaly better to use the GetComponent method so i wrote the following peice of script
```
void Update () {
//Get Mineral Amount
minerals = nexusScript.GetComponent().minerals;
energy = nexusScript.GetComponent().energy;
}
```
in the script called nexus there is a variable named minerals and an other one named energy. but i get the following warnung message:
NullReferenceException: Object reference not set to an instance of an object
place\_stuff.Update () (at Assets/Scripts/place\_stuff.cs:32)
(in line 32 of place stuff is the minerals portion of the code above)
and i dont recieve a message for the energy one. ts most likely a noob mistake so hope you guys can help ty.
---
### Author:  [@robertbu](https://discussions.unity.com/u/robertbu)
#### Post date: [November 13, 2013, 2:24am UTC](https://discussions.unity.com/t/get-a-variable-through-getcomponent/86578/2 "2013-11-13T02:24:45Z")
It is hard to give an exact answer given such a small amount of your code. You are getting the null reference exception because either 1) nexusScript is not initialized to a game object, or 2) the game object nexusScript is initialized to does not have a ‘nexus’ script attached.
As for your problem of modifying a variable in multiple different scripts to match some value, since you are using C#, you can use events and delegates to solve it. It is a bit more advance topic, but if you take the time with the following video, you should be able to use them:
[http://www.youtube.com/watch?v=N2zdwKIsXJs](http://www.youtube.com/watch?v=N2zdwKIsXJs)
If all the variables are in the same script (but attached to multiple game objects), and if the variable must be the same for all the gameObjects, consider using a ‘static’ variable. Variables declared static share a single value among all instances of that class. There are certain “evils” that can come from using static variables, but your problem might be a good place to use them.