Hashtable size() Method in Java
The java.util.Hashtable.size() method of Hashtable class is used to get the size of the table which refers to the number of the key-value pair or mappings in the Table.
Syntax:
Hash_Table.size()
Parameters: The method does not take any parameters.
Return Value: The method returns the size of the table which also means the number of key-value pairs present in the table. Below programs illustrates the working of java.util.Hashtable.size():
Program 1:
Java
// Java code to illustrate the size() methodimport java.util.*;public class Hash_Table_Demo { public static void main(String[] args) { // Creating an empty Hashtable Hashtable<Integer, String> hash_table = new Hashtable<Integer, String>(); // Inserting elements into the table hash_table.put(10, "Geeks"); hash_table.put(15, "4"); hash_table.put(20, "Geeks"); hash_table.put(25, "Welcomes"); hash_table.put(30, "You"); // Displaying the Hashtable System.out.println("Initial table is: " + hash_table); // Displaying the size of the table System.out.println("The size of the table is " + hash_table.size()); }} |
Output:
Initial table is: {10=Geeks, 20=Geeks, 30=You, 15=4, 25=Welcomes}
The size of the table is 5
Program 2:
Java
// Java code to illustrate the size() 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("Initial Table is: " + hash_table); // Displaying the size of the table System.out.println("The size of the table is " + hash_table.size()); }} |
Output:
Initial Table is: {You=30, Welcomes=25, 4=15, Geeks=20}
The size of the table is 4
Note: The same operation can be performed with any type of variation and combination of different data types.
