You can never determine the exact questions an interviewer will ask you, but your research should give you a good idea of the topics the interviewer will cover. Sources of the information you can use to determine this include the job posting, the organization's website, and conversations with current and former employees performing the same job. The more in-depth your research, the better you will perform during the interview.

"Enum instances cannot be created outside of the Enum boundary. This is because Enum doesn't have a public constructor. The compiler generates a lot of code in response to the Enum type declaration and therefore doesn't allow public constructors inside Enum. This requires you to declare Enum instances inside Enum itself."