Java: Example Enum

This article contains a variety of example enums (enumerations) in use.

Simple Enum

The example below is a simple enum example related to temperature.

// enum definition
enum Heat {  
  COLD("Cold"),  
  WARM("Warm"),  
  HOT("Hot");

  String label;

  Heat(String label) {
     this.label = label;
  }

  public void print() {
    System.out.println(label);
  }
} 

// enum usage
Heat myVar = Heat.WARM; 
myVar.print();
// output: "Warm"

Enum Within a Class

The example below contains an enum being used within a class.

public class MyClass {   
  enum Heat {  
    COLD("Cold"),  
    WARM("Warm"),  
    HOT("Hot");

    String label;

    Heat(String label) {
      this.label = label;
    }

    public void print() {
      System.out.println(label);
    }
  } 

  public static void main(String[] args) { 
    Heat myHeat = Heat.COLD; 
    System.out.println(myHeat);  
    myHeat.print();
  } 
} 

Enum Within a Switch Statement

The example below contains an enum being used within a switch statement.

enum Heat {  
  COLD,  
  WARM,  
  HOT  
}  
  
public class EnumExample { 
  public static void main(String[] args) {  
    Heat myVar = Heat.HOT;   
  
    switch(myVar) {  
      case COLD:  
        System.out.println("ice coooollllld!!!");  
        break;  
      case WARM:  
        System.out.println("nice and cozy");  
        break;  
      case HOT:  
        System.out.println("so hot right now!!");  
        break;  
      }  
   }  
} 

Loop Through an Enum

The example below loops through an enum to print out its values.

for (Heat temp : Heat.values()) {
    System.out.println(temp);  
} 

Use a Parameterized Enum

The example below uses a parameterized enum.

public class EnumDemo {
  
  public enum TripCosts {
    FLIGHTS(700), 
    HOTELS(500), 
    FOOD(300), 
    ACTIVITIES(250);

    TripCosts(int price) {
      this.price = price;
    }

    private final int price;

  public int getPrice() {
    return price;
  }
}

public class UsingParameterizedEnum {
  public static void main(String[] args) {
    for (TripCosts f : TripCosts.values()) {
      System.out.print("TripCosts: " + f + ", ");
      if (f.getPrice() >= 4) {
        System.out.print("Expensive, ");
      } else {
        System.out.print("Affordable, ");
      }
      switch (f) {
        case FLIGHTS:
          System.out.println("Flights are expensive");
          continue;
        case HOTELS:
          System.out.println("You're staying VIP!");
          continue;
        case FOOD:
          System.out.println("Good thing you like to each cheap!");
          continue;
        default:
          System.out.println("Option not found. Enjoy your trip!");
      }
    }
  }
}

Summary: Enumeration Examples

• Enumerations (aka "enums") are very helpful for defining and using a fixed set of values instead of relying upon developers to set corresponding transient variables
• Enumerations are easy to create
• Enumerations are easy to use