BCqrstoO BCqrstoO - 3 months ago 19
Java Question

Java enum with multiple value types

Basically what I've done is write an enum for States, and I want to not only be able to access them just as states but also access their abbreviation and whether or not they were an original colony.

public enum States {
...
MASSACHUSETTS("Massachusetts", "MA", true),
MICHIGAN("Michigan", "MI", false),
...; //so on and so forth for all fifty states

private final Object[] values;

States(Object... vals) {
values = vals;
}

public String FULL() {
return (String) values[0];
}

public String ABBR() {
return (String) values[1];
}

public boolean ORIGINAL_COLONY(){
return (boolean) values[2];
}
}


This seems to work as I'd expect it to. I can

System.out.println(States.ALABAMA); // Prints "ALABAMA"
System.out.println(States.ALABAMA.FULL()); // Prints "Alabama"
System.out.println(States.ALABAMA.ABBR()); // Prints "AL"
System.out.println(States.ALABAMA.ORIGINAL_COLONY());// Prints "false"


For this particular scenario involving enums, is this the best way to do this or is there a better way to setup and format this enum? Thanks to all in advance!

Answer

First, the enum methods shouldn't be in all caps. They are methods just like other methods, with the same naming convention.

Second, what you are doing is not the best possible way to set up your enum. Instead of using an array of values for the values, you should use separate variables for each value. You can then implement the constructor like you would any other class.

Here's how you should do it with all the suggestions above:

public enum States {
    ...
    MASSACHUSETTS("Massachusetts",  "MA",   true),
    MICHIGAN     ("Michigan",       "MI",   false),
    ...; // all 50 of those

    private final String full;
    private final String abbr;
    private final boolean originalColony;

    private States(String full, String abbr, boolean originallyColony) {
        this.full = full;
        this.abbr = abbr;
        this.originallyColony = originallyColony;
    }

    public String getFullName() {
        return full;
    }

    public String getAbbreviatedName() {
        return abbr;
    }

    public boolean isOriginalColony(){
        return originalColony;
    }
}