EnumMap vs. Enum values

Question

What's the difference between this:

public enum Direction {
    NORTH(90),
    EAST(0),
    SOUTH(270),
    WEST(180);

    private final int degree_;

    private Direction(int degree) {
        degree_ = degree;
    }

    public int getDegree() {
        return degree_;
    }

    public static void main(String[] args) {
        System.out.println(NORTH.getDegree());
    }
}

and this:

public enum Direction {
    NORTH,
    EAST,
    SOUTH,
    WEST;

    public static void main(String[] args) {
        EnumMap<Direction, int> directionToDegree = new EnumMap<Direction, int>(Direction.class);
        directionToDegree.put(NORTH, 90);
        directionToDegree.put(EAST, 0);
        directionToDegree.put(SOUTH, 270);
        directionToDegree.put(WEST, 180);

        System.out.println(directionToDegree.get(NORTH));
    }
}

Is one easier to read? Is one more flexible? Is one used more conventionally? Does one run faster? Any other pros and cons?

Answer 1

The main use case for the EnumMap is when you want to attach additional data to an enum you don't own. Typically you are using a public library that has an enum and you need to annotate each member with your data.

As a general rule, whenever both approaches are available to you, use the first one.