Exceptions

Procedural Style

In a procedural language the error handling is either done by
checking the return value of a function or checking some other
variable that contains the error. The pseudo code can look like:

      result = function1() ;

      if ( result < 0 )

         //Handle error

      function2() ;

       if ( ErrorCode == 100 )

          //Handle error

The code can easily become very messy. Another way to handle errors and this is
usually a feature in object oriented programming is to use Exceptions. The above
will instead look like:

          try
          {
               result = function1() ;
               function2() ;
          }
         catch ( Exception except )
         {
              //Any error in the try block causes control to come
              //to the catch block.
         }

 The code that can "throw" an error is enclosed in a "try" block. Immediately
 following the "try" block we have a "catch" block. In the "catch" block we
 can handle the error. We  need to have the "catch" following the "try" block else
 we will get a compiler error. Both the "try" and "catch" work hand in hand.