When you run a program, things can go wrong - run time errors. And no amount of coding by the programmer can prevent these things - it   s a user entering a string of text when a number   s required, a needed file having been deleted, or a network connection that   s broken that causes probems.

In traditional coding, it   s standard practise to check for as many of these errors as you can throughout your code, and this often results in a few lines of live code being wrapped in 4 or 5 times that number of lines of error checking ... which catch most but still not all of the errors that may occur.

Exceptions are provided in many modern OO languages - they   re in more recent C++ compilers, for example, as well as in languages like Python and Java. They let you write code where you don   t write the detail of checking for each possible error yourself - rather, you code for the working case and you enclose anything that may go wrong into a try block. Then you provide one or more catch blocks to set up actions that are to be taken if the try block failed to complete.

Great system; often less coding, and with a tendency to fail safe if error conditions that you   ve not explicitly coded for crop up.
(written 2006-07-11 06:14:45)

 C236 - C and C based languages - Exceptions

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