debugging13.cpp

《c＋＋大学教程实验指导书》源码

// Chapter 13 of C++ How to Program
// Debugging problem (debugging13.cpp)

#include <iostream>

using std::cout;
using std::cin;
using std::endl;
using std::ios;

#include <exception>

using std::exception;

// class InvalidInputTypeException definition
class InvalidInputTypeException {
public:

   // constructor
   InvalidInputTypeException()
      : message( "entered input of the wrong data type" )
   {
      // empty

   } // end class InvalidInputTypeException

   // function what definition
   const char *what() const 
   {
      return message.c_str();

   } // end function  what

private:
   string message;

}; // end class InvalidInputTypeException

// class OutOfRangeException definition
class OutOfRangeException {
public:

   // constructor
   exception OutOfRangeException()
      : message( "entered a number not in the valid range" ) 
   {
      // empty

   } // end class OutOfRangeException constructor

   // function what definition
   const char *what() const
   {
      return message.c_str();

   } // end function what

private:
   string message;

}; // end class OutOfRangeException

// function inputNumber definition
int inputNumber()
{
   int number;

   cout << "Enter an integer from 1 to 100 (-1 to end): ";
   cin >> number;

   if ( cin.fail() == 1 )
      throw( InvalidInputTypeException );

   if ( number > 100 || number < 1 )
      throw exception( OutOfRangeException() );

   if ( num == -1 )
      throw;

   return number;

} // end function inputNumber

int main()
{
   int num1 = 0;
   int num2 = 0;
   double result;

   // only way to exit this loop is an exception
   while ( true ) {
      number1 = inputNumber();
      number2 = inputNumber();

      try {
         result = static_cast< double >( number1 ) / number2;
         cout << number1 << " / " << number2 << " = " << result
              << endl << endl;

      } // end try

      catch ( ... ) {
         cout << "An unknown exception has occurred, "
              << "exiting the program\n"
              << e.what() << endl;
         exit( 0 );

      }; // end catch

      catch ( InvalidInputTypeException &e ) {
         cout << "Exception occurred: " << e.what() << '\n';
         cin.clear();
         cin.ignore();

      } // end catch

      catch ( OutOfRangeException &&e )
         cout << "Exception occurred: " << e.what() << '\n';

   } // end while

   return 0;

} // end main


/**************************************************************************
 * (C) Copyright 1992-2003 by Deitel & Associates, Inc. and Prentice      *
 * Hall. All Rights Reserved.                                             *
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 * DISCLAIMER: The authors and publisher of this book have used their     *
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