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Java Collection, HashMap Exercises: Get a set view of the keys contained in this map

Java Collection, HashMap Exercises: Exercise-11 with Solution

Write a Java program to get a set view of the keys contained in this map.

Sample Solution:-

Java Code:

import java.util.*;  
public class Example11 {  
     public static void main(String args[]){  
 
  HashMap<Integer,String> hash_map= new HashMap<Integer,String>();  
  
  hash_map.put(1,"Red");
  hash_map.put(2,"Green");
  hash_map.put(3,"Black");
  hash_map.put(4,"White");
  hash_map.put(5,"Blue");
  
  // get keyset value from map
   Set keyset = hash_map.keySet();
      
  // check key set values
   System.out.println("Key set values are: " + keyset);  
 }
}

Sample Output:

Key set values are: [1, 2, 3, 4, 5]

Java Code Editor:

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Java: Tips of the Day

getEnumMap

Converts to enum to Map where key is the name and value is Enum itself.

public static <E extends Enum<E>> Map<String, E> getEnumMap(final Class<E> enumClass) {
    return Arrays.stream(enumClass.getEnumConstants())
            .collect(Collectors.toMap(Enum::name, Function.identity()));
}

Ref: https://bit.ly/3xXcFZt