Namespaces (C# Programming Guide)
Namespaces are heavily used in C# programming in two ways. First, the .NET Framework uses namespaces to organize its many classes, as follows:
System.Console.WriteLine("Hello World!");
System is a namespace and Console is a class in that namespace. The using keyword can be used so that the complete name is not required, as in the following example:
using System;
Console.WriteLine("Hello"); Console.WriteLine("World!");
For more information, see using Directive (C# Reference).
Second, declaring your own namespaces can help you control the scope of class and method names in larger programming projects. Use the namespace keyword to declare a namespace, as in the following example:
namespace SampleNamespace { class SampleClass { public void SampleMethod() { System.Console.WriteLine( "SampleMethod inside SampleNamespace"); } } }
Namespaces have the following properties:
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They organize large code projects.
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They are delimited by using the . operator.
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The using directive obviates the requirement to specify the name of the namespace for every class.
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The global namespace is the "root" namespace: global::System will always refer to the .NET Framework namespace System.
For more information, see the C# Language Specification. The language specification is the definitive source for C# syntax and usage.
