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()); } } |
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()); } } |
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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