[..] Should you use an interface or an abstract class?
Well, an interface gives you the benefits of an abstract class and the benefits of an interface, so if it’s possible to create your base class without any method definitions or member variables you should always prefer interfaces to abstract classes.
In fact, if you know something is going to be a base class, your first choice should be to make it an interface, and only if you’re forced to have method definitions or member variables should you change to an abstract class.
I use Enums for anything that has multiple nonchanging "type" of something. i.e days of a week.
Why I don't use String in this case is because I can't do switch statement on the String and I can on Enum so for every day of a week I can do something specific.
"While this approach has yet to be widely
adopted, a single-element enum type is the best way to implement a singleton." not gonna paste code read the book it's excellent.
This is an direct excerpt from the excellent book 'Thinking in Java' by Bruce Eckel.
I use Enums for anything that has multiple nonchanging "type" of something. i.e days of a week.
Why I don't use String in this case is because I can't do switch statement on the String and I can on Enum so for every day of a week I can do something specific.
I also use Enum when working with singleton pattern, Check the Effective Java book CH2(CHAPTER 2 CREATING AND DESTROYING OBJECTS), quote :
"While this approach has yet to be widely adopted, a single-element enum type is the best way to implement a singleton." not gonna paste code read the book it's excellent.
If I were you I'd firstly read Thinking in java chapter Enumerated Types. Then after that Effective Java chapter 6 and you should be good
Bruce Eckel's Thinking in Java 4th Edition