• Abort program
• Print error message to screen/Write message to log file
• Use assert
• Ignore
• Set some global error indicator
• Status return value
• Status writeback parameter
• Some combination (e.g., print message and abort)

• Not just errors
  • Exceptional situations
  • Situations whose 'handling'~ logic we don't want cluttering up our 'normal' situation code
• Notification occurs in a different manner than usual call/return mechanism
• Involves
  • Handling the exception - catching the exception
  • Signalling an exceptional situation - throwing an exception

• Enclose the possibly offending code in a try block with associated catch blocks.

  				try {
  					code that could potentially cause an exception
  				} catch (exception-declaration) {
  					exception-handling code
  				} catch (exception-declaration) {
  					exception-handling code
  				}
  				... 
  				} catch (exception-declaration) {
  					exception-handling code
  				}
  			

• Each of the catch block arguments (the exception-declarations) are different.
• The catch block matching the type of the exception thrown is executed.

Signalling the Exception

• Use a throw expression

  				throw "Error - concordance word limit exceeded";
  			

• expression type determines which catch block will be executed
  • in above case it would be a catch block of the form

    					catch (char *msg) {
    						...
    					}
    			

• We will use exception classes for our exception objects, whenever possible.

Code for Exception Handling