Map entrySet() method in Java with Examples

The java.util.Map.entrySet() method in Java is used to create a set out of the same elements contained in the map. It basically returns a set view of the map or we can create a new set and store the map elements into them.

Syntax:

map.entrySet()

Parameters: The method does not take any parameter.

Return Value: The method returns a set having same elements as the hash map.

Below programs llustrate the java.util.Map.entrySet() Method:



Program 1: Mapping String Values to Integer Keys.

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code to illustrate the entrySet() method
  
import java.util.*;
  
public class Map_Demo {
    public static void main(String[] args)
    {
        // Creating an empty Map
        Map<Integer, String> map = new HashMap<Integer, String>();
  
        // Mapping string values to int keys
        map.put(10, "Geeks");
        map.put(15, "4");
        map.put(20, "Geeks");
        map.put(25, "Welcomes");
        map.put(30, "You");
  
        // Displaying the Map
        System.out.println("Initial Mappings are: " + map);
  
        // Using entrySet() to get the set view
        System.out.println("The set is: " + map.entrySet());
    }
}

chevron_right






                        filter_none









Output:


Initial Mappings are: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4}
The set is: [20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4]





Program 2: Mapping Integer Values to String Keys.











                                    filter_none




                                    edit

                                    close




                                    play_arrow




                                    link

                                    brightness_4

                                    code
                                




















// Java code to illustrate the entrySet() method 


import java.util.*; 


  


public class Map_Demo { 


    public static void main(String[] args) 


    { 


        // Creating an empty Map 


        Map<String, Integer> map = new HashMap<String, Integer>(); 


  


        // Mapping int values to string keys 


        map.put("Geeks", 10); 


        map.put("4", 15); 


        map.put("Geeks", 20); 


        map.put("Welcomes", 25); 


        map.put("You", 30); 


  


        // Displaying the Map 


        System.out.println("Initial Mappings are: " + map); 


  


        // Using entrySet() to get the set view 


        System.out.println("The set is: " + map.entrySet()); 


    } 


} 



















                        chevron_right







                        filter_none









Output:


Initial Mappings are: {4=15, Geeks=20, You=30, Welcomes=25}
The set is: [4=15, Geeks=20, You=30, Welcomes=25]





Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.


Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Map.html#entrySet()



          
          
          
          

            

    

        My Personal Notes
        arrow_drop_up
    

    

        
        

            
            
        

    


Recommended Posts:
gopaldave
The function of education is to teach one to think intensively and to think critically
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on  the "Improve Article" button below.