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() methodimport 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() methodimport 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.
