public enum ArithmeticOperator {
    // The enumerated values
    ADD, SUBTRACT, MULTIPLY, DIVIDE;

    // Value-specific behavior using a switch statement
    public double compute(double x, double y) {
        switch(this) {
        case ADD:       return x + y;
        case SUBTRACT:  return x - y;
        case MULTIPLY:  return x * y;
        case DIVIDE:    return x / y;
        default: throw new AssertionError(this);
        }
    }

    // Test case for using this enum
    public static void main(String args[]) {
        double x = Double.parseDouble(args[0]);
        double y = Double.parseDouble(args[1]);
        for(ArithmeticOperator op : ArithmeticOperator.values())
            System.out.printf("%f %s %f = %f%n", x, op, y, op.compute(x,y));
    }
}