Java Enum Constructors

In this Java tutorial, you can understand enumeration constructors with the help of a valid example.

Before learning enumeration constructors, please make sure you understandJava enumeration.

In Java, enumeration classes may contain constructors similar to those of regular classes. These enumeration constructors are

• private-Accessible within the class
  or

• package-private - Accessible within the package

Example: enumeration constructor

enum Size {
　　　//Enumeration constants, call enumeration constructor
　　　SMALL("Size small."),
　　　MEDIUM("Size medium."),
　　　LARGE("Size large."),
　　　EXTRALARGE("Size extra large.");
　　　private final String pizzaSize;
　　　//Private enumeration 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 Result

The size is very small.

In the above example, we create an enum Size. It contains a private enum constructor. The constructor takes a string value as a parameter and assigns the 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 assign SMALL to the enum variable size. Then, the constant SMALL calls the constructor Size with a string parameter.

　Finally, we use size to call getSize().