Skip to content
Related Articles

Related Articles

Improve Article

IdentityHashMap isEmpty() Method in Java

  • Last Updated : 23 Jul, 2018
Geek Week

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.






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

Program 2: For an empty IdentityHashMap




// 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());
    }
}
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 Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.




My Personal Notes arrow_drop_up
Recommended Articles
Page :