>>>>> "BM" == Brandon McCaig <bamcc...@gmail.com> writes:
BM> On Sun, Sep 4, 2011 at 11:53 PM, flebber <flebber.c...@gmail.com> wrote: >> For this example. the first two assignments work okay, but then at $c >> if I do not declare my local then I get an error. $d also requires >> that it be assigned using my, though it is directly the same as $b, my >> assumption here is that $d required explicit assignment as it used the >> explicitly assigned variable $c (could be wrong). >> >> Why from $c was "my" required? BM> *snip* >> $a = 6*9; >> print "six times 9 is ", $a, "\n"; >> $b = $a + 3; >> print "plus three is ", $b,"\n"; >> my $c = $b/3; >> print "Divided by 3 is ", $c, "\n"; >> my $d = $c + 1; >> print "plus one is ", $d, "\n"; BM> $a and $b are special global variables used by sort. :) See perldoc BM> perlvar and/or perldoc -f sort. :) So, in short, $a and $b already BM> existed, so there was no problem using them without declaring them BM> first. You should ALWAYS declare your variables. :) You either use BM> 'my' for a lexical scope or 'our' for module scope. :) There is also there is no such thing as module scope. our declares package globals and give them a short name in a lexical scope. BM> 'local', but I'm not going to attempt to explain how that works so BM> early in the morning. You should be able to learn about each using BM> perldoc -f though. To be safe and clear you shouldn't use the names $a BM> and $b unless you are actually using them within a sort. single letter variable names are bad in general. they tell you nothing about the use and content of the variable. about the only exception are $i and $j for array/matrix indexing and the aforementioned $a and $b for scoping. uri -- Uri Guttman -- uri AT perlhunter DOT com --- http://www.perlhunter.com -- ------------ Perl Developer Recruiting and Placement Services ------------- ----- Perl Code Review, Architecture, Development, Training, Support ------- -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
