Question

I’m just getting the hang of OOP and have been playing around with Java a lot. One of the troubles I have is deciding whether I need a private instance field for a particular class. Is there a rule of thumb I should be using in terms of whether I need to make something a private instance field of not?

Thanks.

Answer 1

If it´s a natural part of the object or something the object needs to perform some task on a regular basis then by all means make it an attribute. If it is a constant then you should make it a public class variable (or rather a constant :P). That is, declare it “public static final w/e”

Public instance variables are not used as often because it often leads to messier code. Think as previously stated of the instance variables (or attributes) as the objects state. It´s usualy clearer to change the objects state by performing operations on it rather than juggle publics around. Good luck.