Should a private final field be static too?

Question

I was wondering, if I have this field in my class : private final int foo = ..., should I put it in static private static final int foo = ...? Beca

Answer 1

There is a big difference between the two non-access modifiers.

• final means your variable can be assigned a value once.
• static sets its scope to pertain to the class (rather than an instance or a local context).

There is no reason why they should go together unless by design.

A static final variable is de facto a constant.

For instance, fields declared in interfaces are implicitly public, static and final.

Amongst the usage examples for final, non static fields you can find:

• fields declared outside an anonymous class and being referenced inside it
• local fields (declared in a method's body) being referenced inside a local class (declared in the same method's body)
• etc...