Java enum Constructor

Before you learn about enum constructors, make sure to know about Java enums.

In Java, an enum class may include a constructor like a regular class. These enum constructors are either

• private - accessible within the class
  or
• package-private - accessible within the package

Example: enum Constructor

enum Size {

   // enum constants calling the enum constructors 
   SMALL("The size is small."),
   MEDIUM("The size is medium."),
   LARGE("The size is large."),
   EXTRALARGE("The size is extra large.");

   private final String pizzaSize;

   // private enum constructor
   private Size(String pizzaSize) {
      this.pizzaSize = pizzaSize;
   }

   public String getSize() {
      return pizzaSize;
   }
}

class Main {
   public static void main(String[] args) {
      Size size = Size.SMALL;
      System.out.println(size.getSize());
   }
}

Output

The size is small.

In the above example, we have created an enum Size. It includes a private enum constructor. The constructor takes a string value as a parameter and assigns value to the variable pizzaSize.

Since the constructor is private, we cannot access it from outside the class. However, we can use enum constants to call the constructor.

In the Main class, we assigned SMALL to an enum variable size. The constant SMALL then calls the constructor Size with string as an argument.

Finally, we called getSize() using size.