Java.util.EnumMap.keySet() Method

Description

The java.util.EnumMap.keySet() method returns a Set view of the keys contained in this map.

Declaration

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

public Set<K> keySet()

Parameters

• NA

Return Value

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

Exception

• NA

Example

The following example shows the usage of java.util.EnumMap.keySet() method.

package com.tutorialspoint;

import java.util.*;

public class EnumMapDemo {

   // create an enum
   public enum Numbers {

      ONE, TWO, THREE, FOUR, FIVE
   };

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

      // print the map
      System.out.println("Map: " + map);

      // create a new set and return the set view of the keys contained
      Set<Numbers> set = map.keySet();

      // print the set
      System.out.println("Set: " + set);

   }
}

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

Map: {ONE=1, TWO=2, THREE=3, FOUR=4}
Set: [ONE, TWO, THREE, FOUR]