What is the difference between referencing a field by class and calling a field by object?

Question

I have noticed that there are times when coding in Java that I have seen fields called by method:

System.out.println(object.field);

and

Answer 1

My intuition is that the class calling will be used for static fields

Yes SomeClass.field can be used only if field is static. In this case you can also access it via reference like someClassRef.field but this code will be changed by compiler to ReferenceType.field anyway. Also it can cause some misunderstandings (it may seem that you are trying to use non-static field) so it is better to use static fields by its class.

If field is not static then it must belong to some instance so you will have to call it via reference someClassRef.field