1   // Fig. 21.5: fig21_05.cpp
2   // Demonstrating namespaces.
3   #include <iostream>
4   using namespace std;  // use std namespace
5   
6   int myInt = 98;       // global variable
7   
8   namespace Example {
9      const double PI = 3.14159;
10     const double E = 2.71828; 
11     int myInt = 8;
12     void printValues();
13  
14     namespace Inner {   // nested namespace
15        enum Years { FISCAL1 = 1990, FISCAL2, FISCAL3 };
16     }
17  }
18  
19  namespace {           // unnamed namespace
20     double d = 88.22; 
21  }                     
22  
23  int main()
24  {
25     // output value d of unnamed namespace
26     cout << "d = " << d;
27  
28     // output global variable
29     cout << "\n(global) myInt = " << myInt;
30  
31     // output values of Example namespace
32     cout << "\nPI = " << Example::PI << "\nE = "
33          << Example::E << "\nmyInt = " 
34          << Example::myInt << "\nFISCAL3 = "
35          << Example::Inner::FISCAL3 << endl;
36  
37     Example::printValues();  // invoke printValues function
38  
39     return 0;
40  }
41  
42  void Example::printValues() 
43  {
44     cout << "\n\nIn printValues:\n" << "myInt = "
45          << myInt << "\nPI = " << PI << "\nE = "
46          << E << "\nd = " << d << "\n(global) myInt = "
47          << ::myInt << "\nFISCAL3 = " 
48          << Inner::FISCAL3 << endl;
49  }
}