namespace (C# Reference)
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.
namespace SampleNamespace { class SampleClass { } interface SampleInterface { } struct SampleStruct { } enum SampleEnum { a, b } delegate void SampleDelegate(int i); namespace SampleNamespace.Nested { class SampleClass2 { } } }
Within a namespace, you can declare one or more of the following types:
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 (C# Reference).
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:
namespace MyCompany.Proj1 { class MyClass { } } namespace MyCompany.Proj1 { class MyClass1 { } }
The following example shows how to call a static method in a nested namespace.
namespace SomeNameSpace { public class MyClass { static void Main() { Nested.NestedNameSpaceClass.SayHello(); } } // a nested namespace namespace Nested { public class NestedNameSpaceClass { public static void SayHello() { Console.WriteLine("Hello"); } } } } // Output: Hello
For more information, see the C# Language Specification. The language specification is the definitive source for C# syntax and usage.
