What Is Namespace?

Question

Hi We use namespaces for grouping the related classes.What Is Means Related classes? Any One Can You Explain? Thanks In Advance Moulali.

Brajesh Kumar · Answer

NameSpace is the Logical group of types or we can say namespace is a container (e.g Class Structures Interfaces Enumerations Delegates etc.) example System.IO logically groups input output related features  System.Data.SqlClient is the logical group of ado.net Connectivity with Sql server related features. In Object Oriented world many times it is possible that programmers will use the same class name Qualifying NameSpace with class name can avoid this collision. Example :- // Namespace Declaration using System; // The Namespace namespace MyNameSpace { // Program start class class MyClass { //Functionality } } Namespaces allow you to create a system to organize your code. A good way to organize your namespaces is via a hierarchical system. You put the more general names at the top of the hierarchy and get more specific as you go down. This hierarchical system can be represented by nested namespaces . Bellow shows how to create a nested namespace . By placing code in different sub-namespaces you can keep your code organized. // Namespace Declaration using System; // The Namespaces namespace MyNameSpace { namespace Video { // Program start class class MyVideo { //Functionality public static void play () { //.. } } } namespace Audio { // Program start class class MyAudio { //Functionality public static void play() { //.. } } } } Here i provides an example of how to call namespace members with fully qualified names. A fully qualified name contains every language element from the namespace name down to the method call. At the top of the listing there is a nested namespace tutorial within the MyNameSpace namespace with class Video Audio and method play() .Here we calls this method with the fully qualified name : MyNameSpace . Video.MyVideo . play () MyNameSpace . Audio . MyAudio . play () If we call play method in the same namespace then no need to include MynameSpace at the begin e.g. Video . play () . Now implement this by using directive using MyNameSpace.Video; using MynameSpace.Audio; public void call() { Video . play () } If our method would not be static then make instance then call by the object of the class.

Brajesh Kumar · Answer

The namespace keyword is used to declare a scope that contains a set of related objects. You can use a namespace to organize code elements and to create globally unique types. C# namespace SampleNamespace { class SampleClass { } interface SampleInterface { } struct SampleStruct { } enum SampleEnum { a b } delegate void SampleDelegate( int i); namespace SampleNamespace.Nested { class SampleClass2 { } } } Remarks Within a namespace you can declare one or more of the following types: another namespace class interface struct enum delegate Whether or not you explicitly declare a namespace in a C# source file the compiler adds a default namespace. This unnamed namespace sometimes referred to as the global namespace is present in every file. Any identifier in the global namespace is available for use in a named namespace. Namespaces implicitly have public access and this is not modifiable. For a discussion of the access modifiers you can assign to elements in a namespace see Access Modifiers. It is possible to define a namespace in two or more declarations. For example the following example defines two classes as part of the MyCompany namespace: C# namespace MyCompany.Proj1 { class MyClass { } } namespace MyCompany.Proj1 { class MyClass1 { } }