> Hello, > > Exceptions like the name suggested, is to mark something that you are not > suppose to expect. > For example while getting a data something went wrong, like disconnection, > wrong size of data etc... > > The usage of exception is very costly in performance, and there for should > use only on specific events imho. > > But we use exceptions even on places such as StrToInt, when the string is > not an integer number, but we can expect to either have a number or > something else. So why use an exception there ? > > What do you think on this subject ? How would you choose when or where to > use exceptions and why there ? > > Ido
This is a difficult question that cost me many nights of sleep. The TryStrToInt function is better than StrToInt for checking whether the string is valid number. In this TryStrToInt function you just check for TRUE or FALSE instead of exceptions. IF you look at the source code of TryStrToInt in delphi, it just wraps the old Val() procedure. So let me as this question.. why is it that TryStrToInt is useful if we have exceptions? isn't it ambiguous to offer people two ways of doing the same thing? answer: sometimes exceptions really aren't any cleaner than using regular programming logic to check for errors. Now another problem with exceptions is that you don't know for sure where an exception will occur in code, whereas if someone ignores the error return value, you can see it in the code that they have ignored it. _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
