When does null referenceexception occur in Unity?
NullReferenceException happens when your script code tries to use a variable which isn’t set (referencing) and object. The error message that appears tells you a great deal about where in the code the problem happens.
Where to store reference to scripta in Unity?
Store the reference to scriptA in a field on your PlayerUI. Then you can access it from within that class. kru is correct. Also, at line #15, you are accessing currentHealth as a static variable. If currentHealth is defined as public static int currentHealth then you can do that.
What to do when you get an error message in Unity?
If you double-click on the error message in the console window, Unity will (with a few exceptions) highlight the GameObject in the hierarchy that threw the error, and open your code editor and highlight the line of the script where the error occurred.
What does it mean when a reference type is null?
Reference types default to null to indicate that they are not referencing any object. Hence, if you try and access the object that is being referenced and there isn’t one, you will get a NullReferenceException. When you get a NullReferenceException in your code it means that you have forgotten to set a variable before using it.
How to check if an ad object is null?
Your script should either check if it is null or you should not destroy the object. This is the script for the ad and is attached to the respawn button. OnClick of the respawn button calls ShowAd ()
How to check if an object is null in Unity?
The basic C# “x==null” already checks if the reference is null. Unity overloads it to first check if the object is being destroyed and if not, then to default to regular “x==null”. And the command “x.Equals (null)” is always false; it can never be true because if x was null it would throw a null reference exception.
Why does unity overload return true when an object is null?
If you check in code if it equals null, it will return true because Unity overloads “== null” to return true when an object is either actually null OR it’s in the process of being destroyed. That’s not a null reference error, it’s an “Object has been destroyed” error. It means you called Destroy () on either that collider or its parent GameObject.