Enum Map

Java EnumMap class is the specialized Map implementation for enum keys. It inherits Enum and AbstractMap classes.

the Parameters for java.util.EnumMap class.

K: It is the type of keys maintained by this map. V: It is the type of mapped values.

Enum Map Book Example

import java.util.*;
class Book {
int id;
String name,author,publisher;
int quantity;
public Book(int id, String name, String author, String publisher, int quantity) {
    this.id = id;
    this.name = name;
    this.author = author;
    this.publisher = publisher;
    this.quantity = quantity;
}
}
public class EnumMapExample {
// Creating enum
    public enum Key{
           One, Two, Three
           };
public static void main(String[] args) {
    EnumMap<Key, Book> map = new EnumMap<Key, Book>(Key.class);
    // Creating Books
    Book b1=new Book(101,"Let us C","Yashwant Kanetkar","BPB",8);
    Book b2=new Book(102,"Data Communications & Networking","Forouzan","Mc Graw Hill",4);
    Book b3=new Book(103,"Operating System","Galvin","Wiley",6);
    // Adding Books to Map
       map.put(Key.One, b1);
       map.put(Key.Two, b2);
       map.put(Key.Three, b3);
    // Traversing EnumMap
       for(Map.Entry<Key, Book> entry:map.entrySet()){
            Book b=entry.getValue();
            System.out.println(b.id+" "+b.name+" "+b.author+" "+b.publisher+" "+b.quantity);
        }
}
}