Question

I usually don’t post noob questions but…. I am missing something since I began programming.

Let’s imagine a pojo entity object, with several properties name, description and so on. One of these is “direction” which can only be “IN” or OUT.

What’s the best data type for that property?
I could use a Boolean, assuming for example true as in and false as out. Or maybe I can use a single char ‘I’ and ‘o’, or an “enum”..

Consider I will use this object with hibernate, the property will go on a table’s column. So… What’s the best data type for the column, too?

Thank you

Answer 1

I would suggest Enum.

Advantages:

• You can extend the set of possible values of the variable later on
  (should that become necessary).
• The names of the values contain valuable meaning about the semantics of the values.
• Your programming language will help you with type checks.

Of course, that means you should use descriptive names for your enum values…