IdentityHashMap isEmpty() Method in Java

The java.util.IdentityHashMap.isEmpty() method of IdentityHashMap class is used to check for the emptiness of the map. The method returns True if no key-value pair or mapping is present in the map else False.

Syntax:

Identity_Hash_Map.isEmpty()

Parameters: The method does not take any parameters.

Return Value: The method returns boolean true if the map is empty or does not contain any mapping pairs else boolean false.

Below programs illustrates the working of java.util.IdentityHashMap.isEmpty() method:
Program 1: Mapping String Values to Integer Keys.



filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code to illustrate the isEmpty() method
import java.util.*;
  
public class Identity_Hash_Map_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty IdentityHashMap
        Map<String, Integer> identity_hash = new 
                     IdentityHashMap<String, Integer>();
  
        // Mapping int values to string keys
        identity_hash.put("Geeks", 10);
        identity_hash.put("4", 15);
        identity_hash.put("Geeks", 20);
        identity_hash.put("Welcomes", 25);
        identity_hash.put("You", 30);
  
        // Displaying the IdentityHashMap
        System.out.println("The Mappings are: "+
                                      identity_hash);
  
        // Checking for the emptiness of Map
        System.out.println("Is the map empty? "+
                           identity_hash.isEmpty());
    }
}

chevron_right


Output:

The Mappings are: {Geeks=20, Welcomes=25, You=30, 4=15}
Is the map empty? false

Program 2: For an empty IdentityHashMap

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code to illustrate the isEmpty() method
import java.util.*;
  
public class Identity_Hash_Map_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty IdentityHashMap
        Map<String, Integer> identity_hash = new 
                  IdentityHashMap<String, Integer>();
  
        // Displaying the IdentityHashMap
        System.out.println("The Mappings are: "+
                                      identity_hash);
  
        // Checking for the emptiness of Map
        System.out.println("Is the map empty? "+
                            identity_hash.isEmpty());
    }
}

chevron_right


Output:

The Mappings are: {}
Is the map empty? true

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

All methods of Java.util.IdentityHashMap Class

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.




My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

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.