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Passing values from one script to another without a game object in the scene

I’ve found a lot of information on passing parameters from one script to another when a game object is present in the hierarchy. My problem is that my Transform object is created on the fly using Instantiate(myPrefab). Is there any way to access the position of myPrefab game object from another script?

You could store a reference to the instantiated GameObject after it has been instantiated (see example below). If there are more GameObjects, use a list to store them instead.
Call the InstantiateGO() and GetGOPosition() where it makes sense for you.
public class YourClass: MonoBehaviour
{
public GameObject yourPrefab;
public GameObject yourGameObject;
// Use this for initialization
void Start ()
{
}
// Update is called once per frame
void Update ()
{
}
void InstantiateGO()
{
yourGameObject = Instantiate(yourPrefab); // assign the newly instantiated GameObject to yourGameObject
}
void GetGOPosition()
{
var x = yourGameObject.position;
//Do something here
}
}

How to call a public static variable from another class, change its value and then check that its changed from its original class [duplicate]

So im trying to change a variable in another script by touching a cube.
Current setup
1x Player
1x Enemy
Each with their own script Enemy_Stats & Character_Stats
As you can see in this little snippet it's quite a workaround to access the variable from another script.
void OnCollisionEnter(Collision collision)
{
if (collision.gameObject.tag == "Enemy")
{
collision.gameObject.GetComponent<Enemy_Stats>().Health =
collision.gameObject.GetComponent<Enemy_Stats>().Health
- gameObject.GetComponent<Character_Stats>().AttackDamage;
if (collision.gameObject.GetComponent<Enemy_Stats>().Health <= 0)
{
Destroy(collision.gameObject);
}
}
}
Iam new to Unity, but isn't there a way to just refer it with something like:
collision.Health?

How to access variables/functions from another Class. The variable or function you want to access or called must be public not private.
public class ScriptA : MonoBehaviour{
public int playerScore = 0;
void Start()
{
}
public void doSomething()
{
}
}
Access variable playerScore in ScriptA from ScriptB. First, find the GameObject that the script or component is attached to with the GameObject.Find function then use the GetComponent function to retrieve that script or component that is attached to it.
public class ScriptB : MonoBehaviour{
ScriptA scriptInstance = null;
void Start()
{
GameObject tempObj = GameObject.Find("NameOfGameObjectScriptAIsAttachedTo");
scriptInstance = tempObj.GetComponent<ScriptA>();
//Access playerScore variable from ScriptA
scriptInstance.playerScore = 5;
//Call doSomething() function from ScriptA
scriptInstance.doSomething();
}
}

No since Health is not part of the collision object, but Enemy_Stats. You can cache a Component (that's what Enemy_Stats is) if you use it multiple times to save you some typing (and some performance, but that is rather marginal for this example). Also you can cache "known" components like in this case Player_Stats. You can do this e.g. in Start or with a public variable and the inspector.
What you should probably do though is to make the enemy be responsible for his life and not the player, so move the Destroy-part to Enemy_Stats (into the Health property to be exact).

The first thing to make this shorter (and eventually faster) would be to store this: gameObject.GetComponent<Character_Stats>() on Start() in a private variable (you should avoid calling GetComponent on a frequent basis if you can avoid it).
For the Health variable, a way of avoiding GetComponent calls could be caching: you create a Dictionary<GameObject, Enemy_Stats> and read from that as soon as this gameobject collided once

At the very beginning i mean in Awake() method you can find a game-object with tag
and get it's Heath after that in Collision() method you should just decrease the health but, here the condition is there is only one enemy and only one player.

Unity C# store script in variable

I can store a GameObject within a variable with something like:
GameObject Target = SomeGameobject;
How do i do that for a script?
SomeVariableDefinition TargetStatus = Target.GetComponent<Status>();
What is the variable? Is there such a thing?
Thanks in advance, Sorry for the bad english.

Just like to store a game-object, you can also save any script.
GameObject Target = SomeGameobject; //Gameobject sotre
You need to remeber always that game-object is also a script.
Status TargetStatus = Target.GetComponent<Status>();//Status script ref store in TargetStatus Variable
Variable type should need to be compatible with assigned object type(in our case script name)

I assume you are asking how to get a reference of a script that is attached to another GameObject.
You are almost correct. The type on the left and the type in the GetComponent must match.
SomeVariableDefinition TargetStatus = Target.GetComponent<SomeVariableDefinition>();
OR
Status TargetStatus = Target.GetComponent<Status>();
Understand that if the Target GameObject does not have that script you want to access, it will return null.
Below is full Example of how to access Another script instance, variable or function from another script.
public class ScriptA : MonoBehaviour{
public int playerScore = 0;
void Start()
{
}
public void doSomething()
{
}
}
Now, you can access variable playerScore in ScriptA from ScriptB.
public class ScriptB : MonoBehaviour{
ScriptA scriptInstance = null;
void Start()
{
GameObject tempObj = GameObject.Find("NameOfGameObjectScriptAIsAttachedTo");
scriptInstance = tempObj.GetComponent<ScriptA>();
//Access playerScore variable from ScriptA
scriptInstance.playerScore = 5;
//Call doSomething() function from ScriptA
scriptInstance.doSomething();
}
}

Unity3D: Script variables inconsistences using OnTriggerEnter2D

I have the object that have the script component.
public class TeleportReference : MonoBehaviour {
private GameObject reference;
void Start () {
reference = null;
}
public void SetReference(GameObject other){
reference = other;
}
public GameObject GetReference(){
return reference;
}
Now if I search for an object and test the script variables
GameObject test = GameObject.FindGameObjectWithTag("Water");
print(test);
print(test.GetComponent<TeleportReference>());
print(test.GetComponent<TeleportReference>().GetReference());
it works just fine and GetReference() return the variable I stored.
But now if I use it whithin OnTriggerEnter2D
private void OnTriggerEnter2D(Collider2D other)
{
if (other.tag == "Water")
{
print(other);
print(other.gameObject);
print(other.GetComponent<TeleportReference>());
print(other.GetComponent<TeleportReference>().GetReference());
}
}
GetReference() return null (or other variable that I used during Start() of TeleportReference class).
All other testing outputs remain the same.
Could anyone give a hint why this could happen? Does that mean that GetComponent created new instance of TeleportReference in second case?

GetComponent did not create a new instance of TeleportReference in second case. I have similar code in one of my projects and I haven't had any problems. So in this case I would look to see if the problem is somewhere else. Are you sure it's the same "Water" object? Do you have multiple objects with "Water" tag? Are you colliding before reference is assigned? There could be a myriad of things going on. Just test to narrow it down.
For example try performing an action on the other.gameObject object to verify it's the right object, like deactivating it. Also try using other.gameObject.GetComponent (not sure if this makes a difference).

Found the issue. It was in the order of assigning variables. That is - changes were made apperantly before Start() function was called. Thus at some point of the code the stored value was overritten back to null.
This works fine:
public class TeleportReference : MonoBehaviour {
private GameObject reference;
void Awake () {
reference = null;
}
public void SetReference(GameObject other){
reference = other;
}
public GameObject GetReference(){
return reference;
}
Thanks everyone for comments, that really helped me in debugging.

How do I pass variable from one script to another C# Unity 2D?

For example I have a variable (public static float currentLife) in script "HealthBarGUI1" and I want to use this variable in another script.
How do I pass variable from one script to another C# Unity 2D?

You could do something like this, because currentLife is more related to the player than to the gui:
class Player {
private int currentLife = 100;
public int CurrentLife {
get { return currentLife; }
set { currentLife = value; }
}
}
And your HealthBar could access the currentLife in two ways.
1) Use a public variable from type GameObject where you just drag'n'drop your Player from the Hierarchy into the new field on your script component in the inspector.
class HealthBarGUI1 {
public GameObject player;
private Player playerScript;
void Start() {
playerScript = (Player)player.GetComponent(typeof(Player));
Debug.Log(playerscript.CurrentLife);
}
}
2) The automatic way is achieved through the use of find. It's a little slower but if not used too often, it's okay.
class HealthBarGUI1 {
private Player player;
void Start() {
player = (Player)GameObject.Find("NameOfYourPlayerObject").GetComponent(typeof(Player));
Debug.Log(player.CurrentLife);
}
}
I wouldn't make the currentLife variable of your player or any other creature static. That would mean, that all instances of such an object share the same currentLife. But I guess they all have their own life value, right?
In object orientation most variables should be private, for security and simplicity reasons. They can then be made accessible trough the use of getter and setter methods.
What I meant by the top sentence, is that you also would like to group things in oop in a very natural way. The player has a life value? Write into the player class! Afterwards you can make the value accessible for other objects.
Sources:
https://www.youtube.com/watch?v=46ZjAwBF2T8
http://docs.unity3d.com/Documentation/ScriptReference/GameObject.Find.html
http://docs.unity3d.com/Documentation/ScriptReference/GameObject.GetComponent.html

You can just access it with:
HealthBarGUI1.currentLife
I'm assuming that HealthBarGUI1 is the name of your MonoBehaviour script.
If your variable is not static and the 2 scripts are located on the same GameObject you can do something like this:
gameObject.GetComponent<HealthBarGUI1>().varname;

//Drag your object that includes the HealthBarGUI1 script to yourSceondObject place in the inspector.
public GameObject yourSecondObject;
class yourScript{
//Declare your var and set it to your var from the second script.
float Name = yourSecondObject.GetComponent<HealthBarGUI1>().currentLife;
}

TRY THIS!
//Drag your object that includes the HealthBarGUI1 script to yourSceondObject place in the inspector.
public GameObject yourSecondObject;
class yourScript{
//Declare your var and set it to your var from the second script.
float Name = yourSecondObject.GetComponent<HealthBarGUI1>().currentLife;