Defining a Namespace - C++ Statement

C++ examples for Statement:namespace

  1. HOME
  2. C++
  3. Statement
  4. namespace

Introduction

You can define a namespace with these statements: 

namespace myRegion
{
  // function definitions and declarations, global variables, templates, etc.
}

namespace calc
{
  // This defines namespace calc
  // The initial code in the namespace goes here
}
namespace sort
{
  // Code in a new namespace, sort
}
namespace calc
{
  /* This extends the calc namespace
     Code in here can refer to names in the previous
     calc namespace block without qualification */
}

Using a namespace

Demo Code

#include <string>
#include <iostream>

namespace data//  w  ww.jav a2s  . c om
{
  extern const double pi {3.14159265};
  extern const std::string days[]
         {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
}

int main()
{
  std::cout << "pi has the value " << data::pi << std::endl;
  std::cout << "The second day of the week is " << data::days[1] << std::endl;
}

Result


Related Tutorials