On Thu, Sep 17, 2009 at 13:34, Matteo Riva <mura...@gmail.com> wrote: > On Thu, Sep 17, 2009 at 5:56 PM, Uri Guttman <u...@stemsystems.com> wrote: > >> hopefully that explains it. > > Unfortunately, not really :) > > I *know* about the symbol table and typeglobs, but I yet have to > *understand* how it all works, and how to use it. > > My first question here - before everything else - is: why subs to just > return an integer? Why not directly use the number itself? snip
Constants have a value beyond the numbers themselves. Let's suppose that there is a non-POSIX system that has a seek function that works quite a bit like POSIX seek, but it use different values for beginning of file, current location, end of file. If you use literal values in all of your calls, you code won't work on that system. If you use global variables, then you run the risk of those variables being modified accidentally. Constants cannot be easily changed and are therefore safer than globals and since they are defined at compile time, more flexible than literals. The fact that you are asking why would you want constants shows that you are unfamiliar with the many ways variables are used in programming languages. Luckily there was an [article][1] in the [Ironman Perl Challenge][2] recently on just that topic. Read that article and the ones it references, it will likely make you a better programmer. [1] : http://p.einarsen.no/?p=109 [2] : http://www.enlightenedperl.org/ironman.html -- Chas. Owens wonkden.net The most important skill a programmer can have is the ability to read. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
