How do I create enumerations type?

Enumeration is a list of named constants. Every most commonly used programming languages support this feature. But in Java it is officially supported since version 5.0. In Java programming language an enumeration defines a class type. Because an enumeration is a class it can have a constructors, methods, and instance variables.

To create an enumeration we use the enum keyword. For example below is a simple enumeration that hold a list of notebook producers:

package org.kodejava.basic;

public enum Producer {
    ACER, APPLE, DELL, FUJITSU, LENOVO, TOSHIBA
}

Below we use our enumeration in a simple program.

package org.kodejava.basic;

public class EnumDeclaration {
    public static void main(String[] args) {
        // Creates an enum variable declaration and assign the value to
        // Producer.APPLE.
        Producer producer = Producer.APPLE;

        if (producer == Producer.LENOVO) {
            System.out.println("Produced by Lenovo.");
        } else {
            System.out.println("Produced by others.");
        }
    }
}

The ACER, APPLE, DELL identifiers are called enumeration constants. Every named constants have an implicitly assigned public and static access modifiers. Although the enumeration is a class type, to create an enumeration variable we don’t use the new keyword. We create an enum just like creating a primitive type of data, as you can see in the example above.

Wayan

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