What is an example of a Hashtable implementation in C#?

Question

I realize C# and .NET in general already has the Hashtable and Dictionary classes.

Can anyone demonstrate in C# an implementation of a Hashtable?

Update: To clarify, I'm not ncessarily looking for a complete implementation, just an example of the core features of a hashtable (i.e. add,remove, find by key).

Answer 1

Long after the question has been asked, so I don't expect to earn much rep. However I decided it would be fun to write my own very basic example (in less than 90 lines of code):

    public struct KeyValue<K, V>     {         public K Key { get; set; }         public V Value { get; set; }     }      public class FixedSizeGenericHashTable<K,V>     {         private readonly int size;         private readonly LinkedList<KeyValue<K,V>>[] items;          public FixedSizeGenericHashTable(int size)         {             this.size = size;             items = new LinkedList<KeyValue<K,V>>[size];         }          protected int GetArrayPosition(K key)         {             int position = key.GetHashCode() % size;             return Math.Abs(position);         }          public V Find(K key)         {             int position = GetArrayPosition(key);             LinkedList<KeyValue<K, V>> linkedList = GetLinkedList(position);             foreach (KeyValue<K,V> item in linkedList)             {                 if (item.Key.Equals(key))                 {                     return item.Value;                 }             }              return default(V);         }          public void Add(K key, V value)         {             int position = GetArrayPosition(key);             LinkedList<KeyValue<K, V>> linkedList = GetLinkedList(position);             KeyValue<K, V> item = new KeyValue<K, V>() { Key = key, Value = value };             linkedList.AddLast(item);         }          public void Remove(K key)         {             int position = GetArrayPosition(key);             LinkedList<KeyValue<K, V>> linkedList = GetLinkedList(position);             bool itemFound = false;             KeyValue<K, V> foundItem = default(KeyValue<K, V>);             foreach (KeyValue<K,V> item in linkedList)             {                 if (item.Key.Equals(key))                 {                     itemFound = true;                     foundItem = item;                 }             }              if (itemFound)             {                 linkedList.Remove(foundItem);             }         }          protected LinkedList<KeyValue<K, V>> GetLinkedList(int position)         {             LinkedList<KeyValue<K, V>> linkedList = items[position];             if (linkedList == null)             {                 linkedList = new LinkedList<KeyValue<K, V>>();                 items[position] = linkedList;             }              return linkedList;         }     } 

Here's a little test application:

 static void Main(string[] args)         {             FixedSizeGenericHashTable<string, string> hash = new FixedSizeGenericHashTable<string, string>(20);              hash.Add("1", "item 1");             hash.Add("2", "item 2");             hash.Add("dsfdsdsd", "sadsadsadsad");              string one = hash.Find("1");             string two = hash.Find("2");             string dsfdsdsd = hash.Find("dsfdsdsd");             hash.Remove("1");             Console.ReadLine();         } 

It's not the best implementation, but it works for Add, Remove and Find. It uses chaining and a simple modulo algorithm to find the appropriate bucket.