Question

Sorry for probably easy question.

I need array of flags

boolean[20] isTownVisited

But it is not convient to use int in it, i want to use strings:

 isTownVisited[Town.Milan] = true;

or

 return isTownVisited[Town.Rome]

I’ve tried to declare enum

enum Town {Milan, Rome, Florence, Napoli}

But I still can’t use it to index my boolean array. How to fix this problem, may I write something like:

enum Town {Milan = 0, Rome = 1, Florence = 2, Napoli = 3}

Answer 1

You can use an EnumSet.

Set<Town> towns = EnumSet.of(Town.Milan);

towns.add(Town.Rome);

return towns.contains(Town.Napoli);

Under the bonnet the EnumMap and EnumSet uses int ordinal(); The EnumSet uses a bitmap.