Question

I have suffered about JumboEnumSet, but did not find much information about.
when and why do we use JumboEnumSet.Please can anyone explain about JumboEnumSet?

Answer 1

You don’t need to use it explicitly – it’s just an implementation detail. Basically, when an enum is small, EnumSet can use a very efficient representation of the enum as a single int or long (I forget which) with one bit per member. When it has more elements than that representation allows, JumboEnumSet is used instead.

You don’t need to worry about this – just use the members on EnumSet and you’ll be fine. Just be aware that if your enums go over a certain size, then enum sets become more expensive and less efficient.