Exceptions

Curtis Bridges's Avatar, Join Date: Feb 2007
Newbie Member
I am working on a class project as layed out by the instructor. This is in conjunction with Chapter 13 (Exceptions) from the book How To Program in C++ by Deitle 4/e. I am at a total loss on this subject. I thought that catching problems was up to the compiler. I have included Figure 13.1 for an example as per instructions and some code I have been working on. Could someone please look this over and help me get my brain around exceptions or at least this project?


// Fig. 13.1: fig13_01.cpp
// A simple exception-handling example that checks for
// divide-by-zero exceptions.
Code:
#include <iostream>

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

#include <exception>

using std::exception;

// DivideByZeroException objects should be thrown by functions
// upon detecting division-by-zero exceptions
class DivideByZeroException : public exception {

public:

   // constructor specifies default error message
   DivideByZeroException::DivideByZeroException()
      : exception( "attempted to divide by zero" ) {}

};  // end class DivideByZeroException

// perform division and throw DivideByZeroException object if 
// divide-by-zero exception occurs
double quotient( int numerator, int denominator )
{
   // throw DivideByZeroException if trying to divide by zero
   if ( denominator == 0 )
      throw DivideByZeroException(); // terminate function

   // return division result
   return static_cast< double >( numerator ) / denominator;

}  // end function quotient

int main()
{
   int number1;    // user-specified numerator
   int number2;    // user-specified denominator
   double result;  // result of division

   cout << "Enter two integers (end-of-file to end): ";

   // enable user to enter two integers to divide
   while ( cin >> number1 >> number2 ) {
   
      // try block contains code that might throw exception
      // and code that should not execute if an exception occurs
      try {
         result = quotient( number1, number2 );
         cout << "The quotient is: " << result << endl;

      } // end try

      // exception handler handles a divide-by-zero exception
      catch ( DivideByZeroException &divideByZeroException ) {
         cout << "Exception occurred: " << 
            divideByZeroException.what() << endl;

      } // end catch

      cout << "\nEnter two integers (end-of-file to end): ";

   }  // end while

   cout << endl;

   return 0;  // terminate normally

}  // end main
Here is the instructions and code I'm trying to use.


/*Create a program that defines three user defined exception classes
(called ExceptionOne, ExceptionTwo, and ExceptionThree
- with the messages being the same as the name - see Figure 13.1 for an example).
The program should have a loop with a menu with four selections
- Option 1 will throw ExceptionOne, Option 2 ExceptionTwo, Option 3 ExceptionThree
, and Option 4 to exit.
The catch block should only catch the first two exceptions explicitly
with the last exception caught generically.
Make sure the switch logic is inside a try block followed by three catch blocks.
///////////////////////////////////////////////////////////////////////////////*/
Code:
#include <iostream>

#include <exception>

#include <ctime>

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


class BaseException 
{

public:

   // constructor specifies default error message
	ExceptionOne::BaseException ()
	 : ExceptionOne

 }// end class 
class ExceptionOne: public BaseException {

public:

	ExceptionOne::ExceptionOne()
		:ExceptionOne

}// end class



class ExceptionTwo: public ExceptionOne {

public:

   // constructor specifies default error message
  ExceptionTwo::ExceptionTwo()
	  : ExceptionTwo

}  // end class 

class ExceptionThree: public ExceptionTwo {

public:

	ExceptionThree::ExceptionThree()
		:ExceptionThree

}// end class



int main()
{
Any help greatly appreciated. Thanks
0
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
Duplicate of Exceptions. Thread closed.