c#

Question

Hi Why isn't 'using System' sufficient to write all the programs in c#? Why do i need to add different namespaces according to my requirement? For example if i want to use xmlelement I need to use system.xml namespace. Isn't system.xml a part of system namespace? If yes then why do I need to mention 'using System.xml' along with 'using System;?

Vulpes · Answer

In .NET you can 'nest' namespaces - so the System.Xml namespace is nested in the System namespace. However for the purposes of C#'s 'using' directive each namespace is treated separately. So if you want to use a class in the System.Xml namespace (XmlDocument say) without having to 'fully qualify' its name then you must use: using System.Xml; You might reasonably have thought that if you did this: using System; then you'd be able to do this: Xml.XmlDocument doc = new Xml.Document(); but if you try to do that you'll get a compiler error. Curiously though you can do this sort of thing in VB.NET which is a much more forgiving language than C#. For example the following compiles fine: Imports System Module Test Sub Main Dim doc as New Xml.XmlDocument End Sub End Module

vidya · Answer

Thank you all for helping me.

Jignesh Trivedi · Answer

hi system and system.xml both are different namespace. it might possible different namespace with in different assembly or two namespace contain same class. hope this will help you.

Pavan R Bhupalam · Answer

use the namespaces according to reqyiremnts...........

Suthish Nair · Answer

Use it when it required...