How to Add or Update Elements in a HashTable in Java?

In Java, HashTable is a pre-defined class of the collection framework. It is a part of the java.util package and is used to store the key-value pairs in the program. In this article, we will learn how to add and update elements in a HashTable in Java.

Pre-defined Classe to add and update elements in a HashTable

To add or update elements in a HashTable the pre-defined class is:

• HashTable: It is a pre-defined class and it can be used to add or update the elements into the HashMap using the HashTable.

Program to add and update elements in a HashTable in Java

Below is the code implementation to add or update elements in a HashTable.

Original HashMap
key4: ReactJs
key3: JavaScript
key2: CSS
key1: HTML

Updated HashMap
key4: ReactJs
key3: NodeJs
key2: CSS
key1: HTML

Explanation of the Program:

• The above Java program demonstrates adding and updating elements in a Hashtable.
• We have created a Hashtable named hashTable and adds key-value pairs into it.
• Then the original Hashtable is printed.
• After that, it updates the value associated with the key "key3" to "NodeJs" and prints the Hashtable again to show the changes.