Thanks Will but I'll own up to maybe not reading the spec closely enough. Is the string " " to be considered empty? It passes defined() nevertheless...as does the empty string ''. Embarrassing.
> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of > Will of Thornhenge > Sent: Wednesday, August 13, 2003 8:36 PM > To: [EMAIL PROTECTED] > Cc: 'David Byrne' > Subject: Re: empty versus zero > > > I prefer Lynn. Rickards' method to the others I've seen mentioned. > Testing whether the value is defined will always work quietly and > swiftly; several of the other tests proposed will generate warnings > under some conditions, which can really bog down a loop. > > Lynn. Rickards wrote: > > > > > >>I think this is a fairly simple question... > >>How can I count empty values in an array? This count > >>should not include zeros or non-empty values. Below > >>is my current script, but it isn't working properly. > >> > >>I appreciate any assitance that you may provide. > >> > >>Thank you, > >>David > >> > >>#!perl -w > >># Count missing values > >>while (my $line = <>) { > >> chomp ($line); > >> my ($probe_id,$expression) = split /\t/, $line, 2; > >> my @expression = split /\t/, $expression; > >> my $count = 0; > >> foreach my $value (@expression) { > >># if (!$value) { > >> > > > > One way could be to use defined().... > > > > unless(defined($value)) $count += 1; > > > >># } > >> } > >> print "$count\n"; > >>} > > Another way, utilizing the magic "for" and "defined" do with "$_": > > > for (@expression) { $count++ if not defined} > print $count, "\n"; > > > So lots of different ways to do it. > > > -- > Will Woodhull > [EMAIL PROTECTED] > > _______________________________________________ > Perl-Win32-Users mailing list > [EMAIL PROTECTED] > To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs _______________________________________________ Perl-Win32-Users mailing list [EMAIL PROTECTED] To unsubscribe: http://listserv.ActiveState.com/mailman/mysubs
