Hashtable isEmpty() Method in Java

Last Updated : 28 Jun, 2018

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

Syntax:

Hash_Table.isEmpty()

Parameters: The method does not take any parameters.

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

Below programs illustrates the working of java.util.Hashtable.isEmpty() method:
Program 1:

// Java code to illustrate the isEmpty() method
import java.util.*;
  
public class Hash_Table_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty Hashtable
        Hashtable<String, Integer> hash_table = 
                       new Hashtable<String, Integer>();
  
        // Inserting elements into the table
        hash_table.put("Geeks", 10);
        hash_table.put("4", 15);
        hash_table.put("Geeks", 20);
        hash_table.put("Welcomes", 25);
        hash_table.put("You", 30);
  
        // Displaying the Hashtable
        System.out.println("The table is: " + hash_table);
  
        // Checking for the emptiness of Table
        System.out.println("Is the table empty? " + 
                                 hash_table.isEmpty());
    }
}

Output:

The table is: {You=30, Welcomes=25, 4=15, Geeks=20}
Is the table empty? false

Program 2:

// Java code to illustrate the isEmpty() method
import java.util.*;
  
public class Hash_Table_Demo {
    public static void main(String[] args)
    {
  
        // Creating an empty Hashtable
        Hashtable<String, Integer> hash_table = new Hashtable<String, Integer>();
  
        // Displaying the Hashtable
        System.out.println("The table is: " + hash_table);
  
        // Checking for the emptiness of Table
        System.out.println("Is the table empty? " + hash_table.isEmpty());
    }
}

Output:

The table is: {}
Is the table empty? true

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

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