Skip to content
Related Articles

Related Articles

HashMap isEmpty() Method in Java
  • Difficulty Level : Basic
  • Last Updated : 26 Nov, 2018

The java.util.HashMap.isEmpty() method of HashMap 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:

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

chevron_right


Output:

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

Program 2: For an empty HashMap

filter_none

edit
close

play_arrow

link
brightness_4
code

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

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.

My Personal Notes arrow_drop_up
Recommended Articles
Page :