Enumeration in Java (or enum) is a special type in Java whose fields consist of constants. It is used to impose compile-time safety.
For example, consider the days of the week, they are a set of fixed constants, therefore we can have an enum defined:
public enum DayofWeek {
SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY
} Now we can simply check if a variable that stores a day is part of the declared enum. We can also declare enums for non-universal constants, such as:
public enum Jobs {
DEVELOPER, TESTER, TEAM LEAD, PROJECT MANAGER
}This will enforce the job-type to be the constants declared in the Jobs enum. Here's an example enum holding currencies:
public enum Currency {
USD, INR, DIRHAM, DINAR, RIYAL, ASD
}