C# 0 The Complete Reference

Counter

 namespace. Thus, both 

CountDown

 and 

CountUp

 can be referred to directly, without namespace qualification. It doesn’t matter that 

the

Counter

 namespace was split into two parts.

Namespaces Can Be Nested

One namespace can be nested within another. Consider this program:

// Namespaces can be nested.

using System;

namespace NS1 {

  class ClassA {

     public ClassA() {

       Console.WriteLine("constructing ClassA");

    }

  }

  namespace NS2 { // a nested namespace

    class ClassB {

       public ClassB() {

         Console.WriteLine("constructing ClassB");

      }

    }

  }

}

class NestedNSDemo {

  static void Main() {

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PART I

C h a p t e r   1 6 :  

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PART IPART I

    NS1.ClassA a = new NS1.ClassA();

 // NS2.ClassB b = new NS2.ClassB(); // Error!!! NS2 is not in view

    NS1.NS2.ClassB b = new NS1.NS2.ClassB(); // this is right

  }

}

This program produces the following output:

constructing ClassA

constructing ClassB

In the program, the namespace