1: Should have used a library function 2: not 0-indexed (there can be good reasons for this, but the context of the function should at least suggest the reason

1: Should have used a library function 2: not 0-indexed (there can be good reasons for this, but the context of the function should at least suggest the reason) 3: Doesn't handle errors - should throw IllegalArgumentException, and if should do it in the default handler of the switch. If you suddenly see "???" in the UI, it's not easy to track down to this. 4: If for some valid reason this can't be a library function, it should be an enum, and it should be used throughout the code. enum DayOfWeek { MONDAY(1, "Monday"), TUESDAY(2, "Tuesday") ... public int id; public String displayName; // these should be private and have getters according to most style-guides. public DayOfWeek(int id, String displayName) { this.id = id; this.displayName = displayName; } public static DayOfWeek fromId(int id) { for (DayOfWeek d : values()) { if (d.id == id) return d; } throw new IllegalArgumentException("Illegal DayOfWeek id passed: " + id); } }