Java EnumMap entrySet() Method

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Description

The Java EnumMap entrySet() method returns a Set view of the mappings contained in this map.

Declaration

Following is the declaration for java.util.EnumMap.entrySet() method

public Set<Map.Entry<K,V>> entrySet()

Parameters

NA

Return Value

This method returns a set view of the mappings contained in this enum map.

Exception

NA

Getting an Iterator of an EnumMap of Enum, Integer Pairs Example

The following example shows the usage of Java EnumMap entrySet() method to iterate the EnumMap instance. We've created a enum Numbers. Then EnumMap is created of enum Numbers and Integer. Few entries are added and enumMap is printed using entrySet.

package com.tutorialspoint;

import java.util.EnumMap;

public class EnumMapDemo {
   
   // create an enum
   public enum Numbers{ONE, TWO, THREE, FOUR}; 

   public static void main(String[] args) {
      
      EnumMap<Numbers,Integer> map = 
         new EnumMap<>(Numbers.class);

      // associate values in map
      map.put(Numbers.ONE, 1);
      map.put(Numbers.TWO, 2);
      map.put(Numbers.THREE,3);
      map.put(Numbers.FOUR, 4);

      map.entrySet().forEach(e -> System.out.println(e.getKey() +", "+ e.getValue()));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

ONE, 1
TWO, 2
THREE, 3
FOUR, 4

Getting an Iterator of an EnumMap of Enum, String Pairs Example

The following example shows the usage of Java EnumMap entrySet() method to iterate the EnumMap instance. We've created a enum Numbers. Then EnumMap is created of enum Numbers and String. Few entries are added and enumMap is printed using entrySet.

package com.tutorialspoint;

import java.util.EnumMap;

public class EnumMapDemo {
   
   // create an enum
   public enum Numbers{ONE, TWO, THREE, FOUR}; 

   public static void main(String[] args) {
      
      EnumMap<Numbers,String> map = 
         new EnumMap<>(Numbers.class);

      // associate values in map
      map.put(Numbers.ONE, "1");
      map.put(Numbers.TWO, "2");
      map.put(Numbers.THREE,"3");
      map.put(Numbers.FOUR, "4");

      map.entrySet().forEach(e -> System.out.println(e.getKey() +", "+ e.getValue()));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

ONE, 1
TWO, 2
THREE, 3
FOUR, 4

Getting an Iterator of an EnumMap of Enum, Object Pairs Example

The following example shows the usage of Java EnumMap entrySet() method to iterate the EnumMap instance. We've created a enum Numbers. Then EnumMap is created of enum Numbers and Student objects. Few entries are added and enumMap is printed using entrySet.

package com.tutorialspoint;

import java.util.EnumMap;

public class EnumMapDemo {
   
   // create an enum
   public enum Numbers{ONE, TWO, THREE, FOUR}; 

   public static void main(String[] args) {
      
      EnumMap<Numbers,Student> map = 
         new EnumMap<>(Numbers.class);

      // associate values in map
      map.put(Numbers.ONE, new Student(1, "Julie"));
      map.put(Numbers.TWO, new Student(2, "Robert"));
      map.put(Numbers.THREE,new Student(3, "Adam"));
      map.put(Numbers.FOUR, new Student(4, "Jene"));

      map.entrySet().forEach(e -> System.out.println(e.getKey() +", "+ e.getValue()));
   }
}
class Student {
   int rollNo;
   String name;

   Student(int rollNo, String name){
      this.rollNo = rollNo;
      this.name = name;
   }

   @Override
   public String toString() {
      return "[ " + this.rollNo + ", " + this.name + " ]";
   }
}

Output

Let us compile and run the above program, this will produce the following result −

ONE, [ 1, Julie ]
TWO, [ 2, Robert ]
THREE, [ 3, Adam ]
FOUR, [ 4, Jene ]