global and block scope : block scope variable « Language Basics « C++ Tutorial

1. C++ Tutorial
2. Language Basics
3. block scope variable

#include <iostream.h>

int n=0;  //Global

main()
{
        int n = 1;
        {
               int n = 2 ;
               {
                        int n = 3;
                        cout << "In inner  n=" <<n<<endl;
                        cout << "Global    n=" << ::n <<endl;
               }
               cout << "In outter n=" <<n<<endl;
               cout << "Global    n=" <<::n<<endl;
        }
        cout << "In main() n=" << n<<endl;
        return 0 ;
}

In inner  n=3
Global    n=0
In outter n=2
Global    n=0
In main() n=1