// Fig. 6.12: fig06_12.cpp // A scoping example. #include using std::cout; using std::endl; void useLocal( void ); // function prototype void useStaticLocal( void ); // function prototype void useGlobal( void ); // function prototype int x = 1; // global variable int main() { int x = 5; // local variable to main cout << "local x in main's outer scope is " << x << endl; { // start new scope int x = 7; // hides x in outer scope cout << "local x in main's inner scope is " << x << endl; } // end new scope cout << "local x in main's outer scope is " << x << endl; useLocal(); // useLocal has local x useStaticLocal(); // useStaticLocal has static local x useGlobal(); // useGlobal uses global x useLocal(); // useLocal reinitializes its local x useStaticLocal(); // static local x retains its prior value useGlobal(); // global x also retains its value cout << "\nlocal x in main is " << x << endl; return 0; // indicates successful termination } // end main // useLocal reinitializes local variable x during each call void useLocal( void ) { int x = 25; // initialized each time useLocal is called cout << "\nlocal x is " << x << " on entering useLocal" << endl; x++; cout << "local x is " << x << " on exiting useLocal" << endl; } // end function useLocal // useStaticLocal initializes static local variable x only the // first time the function is called; value of x is saved // between calls to this function void useStaticLocal( void ) { static int x = 50; // initialized first time useStaticLocal is called cout << "\nlocal static x is " << x << " on entering useStaticLocal" << endl; x++; cout << "local static x is " << x << " on exiting useStaticLocal" << endl; } // end function useStaticLocal // useGlobal modifies global variable x during each call void useGlobal( void ) { cout << "\nglobal x is " << x << " on entering useGlobal" << endl; x *= 10; cout << "global x is " << x << " on exiting useGlobal" << endl; } // end function useGlobal /************************************************************************** * (C) Copyright 1992-2005 by Deitel & Associates, Inc. and * * Pearson Education, Inc. All Rights Reserved. * * * * DISCLAIMER: The authors and publisher of this book have used their * * best efforts in preparing the book. These efforts include the * * development, research, and testing of the theories and programs * * to determine their effectiveness. The authors and publisher make * * no warranty of any kind, expressed or implied, with regard to these * * programs or to the documentation contained in these books. The authors * * and publisher shall not be liable in any event for incidental or * * consequential damages in connection with, or arising out of, the * * furnishing, performance, or use of these programs. * **************************************************************************/