Is Enum typically used with TreeSet or TreeMap in Java?
Since Enum was only incorporated in Java's most recent iterations, not all Java programmers are up to speed on the technology. This is why interviewers will ask a series of questions to determine your level of knowledge about this topic. They're trying to understand if you are only casually knowledgeable and have limited exposure to Enum or if you use it in your everyday programming.
Since interviewers have been professionally trained to determine your qualifications for a job, they can usually discern whether your knowledge is casual or in-depth about a particular topic. This is why you should always be honest when responding to an interviewer's questions. Attempting to exaggerate your qualifications may get you through the interview, but keep in mind you are expected to perform on the job. This is why it is recommended that you cooperate with the interviewer so you can both determine if this job is appropriate for your skill level.
"The main requirement for using a sorted collection like TreeSet and TreeMap is the implementation of a comparable interface. Since Enum implements a comparable interface by default, it can be safely used inside TreeSet or TreeMap in Java."
