EnumMap

Syntax:

EnumMaps are declared using the following syntax:

public class EnumMap<K extends Enum<K>,V> extends AbstractMap<K,V> implements Serializable, Cloneable

K: It is the type of key we need to add.

V: It is the type of value we need to map to the key.

Also see,  Swap Function in Java

Constructors of EnumMap class:

1. EnumMap(Class<K> keyType): It can be used to create an empty EnumMap with the specified key type.
    
2. EnumMap(EnumMap<K,? extends V> m): It can be used to create an empty EnumMap which has the same Key type as the Enum Map type.
    
3. EnumMap(Map<K,? extends V> m): It can be used to create an EnumMap which is initialized from another map.

Methods of the EnumMap class:

You can also read about the Java Destructor. 

EnumMap Example:

import java.util.*;  
public class EnumMapExample {  

  // creating an enum  
  public enum Days {  
  Monday, Tuesday, Wednesday, Thursday  
  };  

  public static void main(String[] args) {  
  //creating and populating enum map  
  EnumMap<Days, String> map = new EnumMap<Days, String>(Days.class);  
   
   map.put(Days.Monday, "1");  
  map.put(Days.Tuesday, "2");  
  map.put(Days.Wednesday, "3");  
  map.put(Days.Thursday, "4");  

  // printing the map  
  for(Map.Entry m:map.entrySet()){    
      System.out.println(m.getKey()+" "+m.getValue());    
      }   
  }  
}  

Output:

Monday 1
Tuesday 2
Wednesday 3
Thursday 4

Practice by yourself on online java compiler.

You can also read about entryset java here.

Frequently Asked Questions:

Q) What is EnumMap?

A) EnumMap is a special implementation of the Map Interface for the Enums.

Q) Why is EnumMap faster than HashMaps?

A) EnumMaps are faster than HashMaps because they are internally represented as arrays that are highly compact and efficient.

Key Takeaways: 

In this blog, we have covered the following things:

1. We first discussed what are Enums.
2. Then we discussed its different methods and example code.

If you want to learn more about Programming Language and want to practice some questions which require you to take your basic knowledge on Programming Languages a notch higher, then you can visit our here. 

Until then, all the best for your future endeavors, and Keep Coding.