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

for (Direction dir : Direction.values()) {    System.out.println(dir);}

public enum Operation {    ADD {        public double Apply(double x, double y) { return x + y; }    },    SUBTRACT {        public double apply(double x, double y) { return x - y; }    };
    public abstract double apply(double x, double y);}

public enum Pl.NET {    MERCURY (3.303e+23, 2.4397e6),    // other planets...
    private final double mass;   // in kilograms    private final double radius; // in meters
    Planet(double mass, double radius) {        this.mass = mass;        this.radius = radius;    }
    // Getter methods}

Direction dir = Direction.EAST;
switch (dir) {    case NORTH:        System.out.println("Going north");        break;    // other cases...}

public interface Printable {    void print();}
public enum Color implements Printable {    RED, GREEN, BLUE;
    @Override    public void print() {        System.out.println(this.name());    }}

public class Vehicle {    private String make;    private String model;    private int year;
    public Vehicle(String make, String model, int year) {        this.make = make;        this.model = model;        this.year = year;    }
    // Getters and setters for each field}

Vehicle myCar = new Vehicle("Honda", "Civic", 2020);

public void displayInfo() {    System.out.println(make + " " + model + " (" + year + ")");}
public int calculateAge(int currentYear) {    return currentYear - year;}

public class ElectricVehicle extends Vehicle {    private int batteryCapacity;
    public ElectricVehicle(String make, String model, int year, int batteryCapacity) {        super(make, model, year);        this.batteryCapacity = batteryCapacity;    }
    // Additional methods specific to electric vehicles}

public enum CarType {    SEDAN, SUV, HATCHBACK, CONVERTIBLE}

public class Car {    private String make;    private String model;    private CarType type;
    public Car(String make, String model, CarType type) {        this.make = make;        this.model = model;        this.type = type;    }
    // Getters and setters}

public enum EngineType {    DIESEL {        @Override        public void start() {            System.out.println("Starting diesel engine...");        }    },    ELECTRIC {        @Override        public void start() {            System.out.println("Starting electric engine...");        }    };
    public abstract void start();}
public class Car {    private EngineType engineType;
    public Car(EngineType engineType) {        this.engineType = engineType;    }
    public void startCar() {        engineType.start();    }}

public enum CarState {    PARKED, DRIVING, IDLE}
public class Car {    private CarState state;
    public Car() {        this.state = CarState.PARKED;    }
    public void changeState(CarState newState) {        this.state = newState;    }
    // Additional methods}