Looping in a Hashtable

A hashtable is a class in the System.Collections namespace and represents a collection of key-and-value pairs that are organized based on the hash-code of the key. Hashtables are very useful when storing temporary key-value data in memory for quick access. The key of the hashtable is processed through a hashing function that is designed to generate a unique value that is then used as an index into the hashtable to the specific location containing the value. Hashtables strike a balance between resource usage and speed.

You can loop through the Hashtable in various ways (like a number of stuff in .NET). I will show two ...

•       private void loopWithEnumerator(Hashtable hashTable)

        {

           //Set the enumerator for the elements of the dictionary

           IDictionaryEnumerator enumerator = hashTable.GetEnumerator();

           //Loop into collection

           while (enumerator.MoveNext())

           {

              Console.WriteLine("key : " + enumerator.Key.ToString());

              Console.WriteLine("value : " + enumerator.Value.ToString());

           }

        }





•       private void loopWithDictionaryEntry(Hashtable hashTable)

        {

           //Loop into HashTable

           foreach (DictionaryEntry dictionaryEntry in hashTable)

           {

              Console.WriteLine("key : " + dictionaryEntry.Key.ToString());

              Console.WriteLine("value : " + dictionaryEntry.Value.ToString());

           }

        }

I prefer the one with the DictionaryEntry because you can immediately start looping through the hashtable without creating an enumerator (= extra line of code). The foreach statement is actually a wrapper around the enumerator but this won't make a difference in performance I guess ...