package source.enums; public class ComplexEnumsWithInterface { public static void main(String[] args) { DayOfWeek day = DayOfWeek.Wednesday; assert day.persistenceValue == 3; } } enum DayOfWeek implements SomeInterface { Sunday(0), Monday(1), Tuesday(2), Wednesday(3), Thursday(4), Friday(5), Saturday(6); public final int persistenceValue; DayOfWeek(int persistenceValue) { this.persistenceValue = persistenceValue; } } interface SomeInterface { }