Thanks all, For your help Chanan
-----Original Message----- From: perl-boun...@perl.org.il [mailto:perl-boun...@perl.org.il] On Behalf Of Avishalom Shalit Sent: Thursday, January 22, 2009 4:36 PM To: Perl in Israel Subject: Re: [Israel.pm] FW: FW: FW: check if hash is defined - without the keys someone already did, read the replies i think it is 1 key / 8 keys allocated. 2009/1/22 bc.other <bc.ot...@gmail.com>: > Also can anyone tell me what the code: > My $scalar = %hash; > Does ? since I can't find these examples over the docs web page. > Thanks > Chanan > > -----Original Message----- > From: bc.other [mailto:bc.ot...@gmail.com] > Sent: Thursday, January 22, 2009 4:23 PM > To: 'Perl in Israel' > Subject: RE: [Israel.pm] FW: FW: check if hash is defined - without the keys > > I will try to explain what is my purpose: > > I have a script that parsing the ARGV argumemts: tvc1=value > tvc2=value...tvc5=value or tvc=value (which sets all tvc1..tvc5 to specific > value). > Now, I don't know if the arguments exists in the command line of not...since > it an optional arguments. > > So.... > > I can do 2 things: > 1) my $found = 1; > Foreach (keys %tvc)) > { > $found = 0; > } > > "Do something" if ($found); > > 2) "Do something" if (%tvc); > > My question is should option 2 will be OK ? I thought it might send a warnings > but it did when I tried to do: "Do something" if (defined(%tvc)); > which is I believe to be a mistake....since defined doesn't loop on hash keys > - which I thought at start > > I found that option 2 is OK by me - no warnings :-) > Thanks > Chanan > > -----Original Message----- > From: perl-boun...@perl.org.il [mailto:perl-boun...@perl.org.il] On Behalf Of > Avishalom Shalit > Sent: Thursday, January 22, 2009 4:02 PM > To: Perl in Israel > Subject: Re: [Israel.pm] FW: FW: check if hash is defined - without the keys > > i really really recommend the perldoc pages. > "perldoc perltoc" may be a good place to start > > i think that you would really find it useful to study the "context" > aspect of perl > try answering these > > 1) what do you get when you evaluate a list in hash context ? (how > about the other way around?) > 2) what do you get when you evaluate a hash in scalar context? > > --- > as for your first question , > i am not sure why you don't like the idea of looping or why a warning > is better than an explicit check . > > --- > perldoc -f grep > perldoc -f keys > > 2009/1/22 bc.other <bc.ot...@gmail.com>: >> OK, found that I can use the if (%tvc or %tvw) with use strict / warnings it >> works (no need for defined function). >> I understood it returns a value ? but can anyone tell me what this value >> represent ? >> >> I tried this code: >> my %tvc = (1 10); >> my $sc = %tvc; >> >> print $sc; --> printing 1/8 (does it means 1 key, 8 bytes) ? >> Thanks >> Chanan >> >> -----Original Message----- >> From: perl-boun...@perl.org.il [mailto:perl-boun...@perl.org.il] On Behalf >> Of Chanan Berler >> Sent: Thursday, January 22, 2009 3:31 PM >> To: 'Perl in Israel' >> Subject: [Israel.pm] FW: check if hash is defined - without the keys >> >> >> Hi All, >> >> I got a hash with key1…key25, I am looking to know if the keys are defined >> or not. >> But I don't like the way like: if defined($hash{key1}) or ….. >> defined($hash{key5}) >> >> I also don't like much the idea of looping over the keys… >> Q: is there a way to check if hash was defined or not….using the defined >> function showed a warning… >> >> PS: I can stop using the use strict / warnings – and try this if (%tvc or >> %tvw) – and it works… >> But I still want to use them… >> >> Thanks >> Chanan >> >> _______________________________________________ >> Perl mailing list >> Perl@perl.org.il >> http://perl.org.il/mailman/listinfo/perl >> >> _______________________________________________ >> Perl mailing list >> Perl@perl.org.il >> http://perl.org.il/mailman/listinfo/perl >> > > > > -- > -- vish > _______________________________________________ > Perl mailing list > Perl@perl.org.il > http://perl.org.il/mailman/listinfo/perl > > _______________________________________________ > Perl mailing list > Perl@perl.org.il > http://perl.org.il/mailman/listinfo/perl > -- -- vish _______________________________________________ Perl mailing list Perl@perl.org.il http://perl.org.il/mailman/listinfo/perl _______________________________________________ Perl mailing list Perl@perl.org.il http://perl.org.il/mailman/listinfo/perl
