Hi,

I want to give a brief explanation about Dictionary class in Generic namespace.

The Dictionary generic class provides a mapping from a set of keys to a set of values. Each addition to the dictionary consists of a value and its associated key. Retrieving a value by using its key is very fast, close to O(1), because the Dictionary class is implemented as a hash table.

As long as an object is used as a key in the Dictionary, it must not change in any way that affects its hash value. Every key in a Dictionary must be unique according to the dictionary's equality comparer. A key cannot be a null reference (Nothing in Visual Basic), but a value can be, if the value type TValue is a reference type.

__________________
S.Balasubramanian
Nothing is impossible

Syntax:

Dictionary<key, value> sampleDictionary = new Dictionary<key, value>;

As elements are added to a Dictionary, the capacity is automatically increased as required by reallocating the internal array.

Type Parameters

TKey

The type of the keys in the dictionary.

TValue

The type of the values in the dictionary.

__________________
S.Balasubramanian
Nothing is impossible

EX:

Dictionary<string, string> dictionary =
new Dictionary<string, string>();

// Add some elements to the dictionary. There are no
// duplicate keys, but some of the values are duplicates.
dictionary .Add("txt", "notepad.exe");
dictionary .Add("bmp", "paint.exe");
dictionary .Add("dib", "paint.exe");
dictionary .Add("rtf", "wordpad.exe");

// The Add method throws an exception if the new key is
// already in the dictionary.
try
{
dictionary .Add("txt", "winword.exe");
}
catch (ArgumentException)
{
MessageBox.Show("An element with Key = " +txt+ " already exists.");
}

If you try to add a key value as duplicate, an exception is raised.

__________________
S.Balasubramanian
Nothing is impossible

hi ,

The type System.Collections.Hashtable is not supported because it implements
IDictionary.


did u used the Hashtable in Webservice ...it causes error..Did u know....about that...

__________________
The KINGMAKER
Makes Every Thing Possible

Stuffs (My Blog)

Hey,


Pls Check the Supported datatypes

Welcome to the MSDN Library

__________________
The MOSS
Master of Solution Service