The toString() method in the Hashtable class in Java returns a string representation of the key-value mappings contained in the hashtable. The string is in the form of a comma-separated list of key-value pairs enclosed in curly braces.
The toString() method is inherited from the java.util.Hashtable class’s parent class, java.util.Dictionary.
Here’s an example of using the toString() method:
Java
import java.util.Hashtable;public class HashtableExample { public static void main(String[] args) { Hashtable<String, Integer> ht = new Hashtable<>(); ht.put("Alice", 25); ht.put("Bob", 30); ht.put("Charlie", 35); System.out.println(ht.toString()); }} |
{Bob=30, Charlie=35, Alice=25}
The java.util.Hashtable.toString() is an inbuilt method of Hashtable that is used to get a string representation of the objects of Hashtable in the form of a set of entries separated by “, “. So basically the toString() method is used to convert all the elements of Hashtable into String.
Syntax:
Hash_Table.toString()
Parameter: The method does not take any parameters.
Return value: The method returns the set consisting of the string representation of the elements of the hash table.
Below programs illustrate the working of java.util.Hashtable.toString() method:
Program 1:
Java
// Java code to illustrate the toString() 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 string representation System.out.println("The set is: " + hash_table.toString()); }} |
Initial table is: {10=Geeks, 20=Geeks, 30=You, 15=4, 25=Welcomes}
The set is: {10=Geeks, 20=Geeks, 30=You, 15=4, 25=Welcomes}
Program 2:
Java
// Java code to illustrate the toString() 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 string representation System.out.println("The set is: " + hash_table.toString()); }} |
Initial Table is: {You=30, Welcomes=25, 4=15, Geeks=20}
The set is: {You=30, Welcomes=25, 4=15, Geeks=20}
