How to use the Hashtable.elements() method in Java

A HashTable is a collection of key-value pairs. The object to be used as a key should implement the hashCode and equals method, and the key and the value should not be null.

You can read more about the difference between HashTable and HashMap here.

What is the elements() method in Hashtable?

The elements() method can be used to get all the values of the HashTable as an Enumeration object.

Syntax

public Enumeration<V> elements()

Parameters

This method doesn’t take any arguments.

Return value

The elements() method will return an Enumeration of the values of the HashTable.

Code

The example below shows how to use the elements() method.

import java.util.Hashtable;
import java.util.Enumeration;
class HashtableElementsExample {
public static void main( String args[] ) {
Hashtable<Integer, String> map = new Hashtable<>();
map.put(1, "one");
map.put(2, "two");
System.out.println("The map is :" + map );
Enumeration<String> elements = map.elements();
System.out.print("The values are : ");
while(elements.hasMoreElements()) {
System.out.print(elements.nextElement() + ",");
}
}
}

Explanation

In the code above:

  • In line 1, we import the HashTable class.

  • In line 6, we create a HashTable object with the name map.

  • In lines 7 and 8, we use the put() method to add two mappings ({1=one, 2=two}) to the map object.

  • In line 12, we get the values present in the HashTable using the elements() method and store them in the elements variable. Then, we print the elements object by using the while loop, hasMoreElements, and nextElement methods.

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