Java Enumeration

In Java, an Enumeration is a type of object that represents a fixed set of values. An Enumeration can define a set of constants that can be used throughout a program.

Enum can be used in a period with repeated data usage such as years, colors, etc. Let us see how we can declare an enum, use it in variables, and iterate it.

Enum Creation:

With the help of the enum keyword, we can create an enum followed by the name of our choice.
With this specified name, we will access the contents inside the enum.

enum characterNames {
        JohnWick, Naruto, Itachi, Eren
    }

The general convention of using enum data is uppercase; however, it is unimportant.
Here we created enum characterNames and provided some names within.
Let us see how we can store and print this in a variable.

    enum characterNames {
        JohnWick, Naruto, Itachi, Eren
    }
    public static void main(String[] args) {
        characterNames eren = characterNames.Eren;
        System.out.println(eren);
    }
}

Inside the main method, we can access characterNames without class object creation.
Then we store in a variable eren with characterNames as the return type.

Output:

Eren

We can see Eren has been printed from the enum.

public static void main(String[] args) {
        characterNames eren = characterNames.Eren;
        System.out.println(eren.ordinal());
    }

Output:

Using ordinal can return the position number it is situated in the enum.

Loop Enum:

Let us see how we can loop an enum using advanced for loop.

{
        for (characterNames allNames : characterNames.values()) {
            System.out.println(allNames);
        }
    }

Here using the advanced loop, we have used the characterNames, and with the help of method values, we iterated through the entire enum and stored it in allNames.
Once we print allNames, we can see all the names listed inside the enum.

Output:

JohnWick
Naruto
Itachi
Eren