Difference between Hashtable and Dictionary in C#

In C#, Dictionary is a generic collection which is generally used to store key/value pairs. Dictionary is defined under System.Collection.Genericsnamespace. It is dynamic in nature means the size of the dictionary is growing according to the need.

A Hashtable is a collection of key/value pairs that are arranged based on the hash code of the key. Or in other words, a Hashtable is used to create a collection which uses a hash table for storage. It is the non-generic type of collection which is defined in System.Collectionsnamespace. In Hashtable, key objects must be immutable as long as they are used as keys in the Hashtable.

Example: // C# program to illustrate a hashtable using System; using System.Collections;    class GFG {        // Main method     static public void Main()     {            // Create a hashtable         // Using Hashtable class         Hashtable my_hashtable = new Hashtable();            // Adding key/value pair in the hashtable         // Using Add() method         my_hashtable.Add("A1", "Welcome");         my_hashtable.Add("A2", "to");         my_hashtable.Add("A3", "Deepndani");            foreach(DictionaryEntry element in my_hashtable)         {             Console.WriteLine("Key:- {0} and Value:- {1} ",                                element.Key, element.Value);         } }     }

Example // C# program to illustrate Dictionary using System; using System.Collections.Generic;    class Deepndani {        // Main Method     static public void Main()     {            // Creating a dictionary         // using Dictionary<TKey, TValue> class         Dictionary<string, string> My_dict =                      new Dictionary<string, string>();            // Adding key/value pairs in the Dictionary         // Using Add() method         My_dict.Add("1", "Digital Marketing");         My_dict.Add("2", "C++");         My_dict.Add("3", "C#");            foreach(KeyValuePair<string, string> element in My_dict)         {             Console.WriteLine("Key:- {0} and Value:- {1}",                                element.Key, element.Value);         }     } } Output: Key:- 1 and Value:- Digital Marketing Key:- 2 and Value:- C++ Key:- 3 and Value:- C#