C# 0 The Complete Reference

The Specialized Collections

The .NET Framework provides some specialized collections that are optimized to work on a 

specific type of data or in a specific way. These non-generic collection classes are defined 

inside the 

System.Collections.Specialized

 namespace. They are synopsized in the 

following table:

Specialized Collection

Description

CollectionsUtil

Contains factor y methods that create collections.

HybridDictionar y

A collection that uses a 

ListDictionary

 to store key/value pairs 

when there are few elements in the collection. When the collection 

grows beyond a cer tain size, a 

Hashtable

 is automatically used to 

store the elements.

ListDictionar y

A collection that stores key/value pairs in a linked list. It is 

recommended only for small collections.

NameValueCollection

A sor ted collection of key/value pairs in which both the key and 

value are of type 

string

.

OrderedDictionar y

A collection of key/value pairs that can be indexed. 

StringCollection

A collection optimized for storing strings.

StringDictionar y

A hash table of key/value pairs in which both the key and the value 

are of type 

string

.