Hi Deb -
> -----Original Message-----
> From: Deb [mailto:[EMAIL PROTECTED]
> Sent: Saturday, March 01, 2003 7:17 PM
> To: R. Joseph Newton; Perl List
> Subject: Re: shifting through arrays of line data
>
>
> This (code below) makes sense to me, but I was talking this over with a
> co-worker on Friday, and then I tried putting together some 2-dimensional
> hashes - which hurts my head at the moment. So I went to
> perl.plover.com/FAQs to read (again) his article on references,
> and I still
> have a mental block. Conceptually I understand multi-dimensioned
> hashes, but
> in practice I have a LOT of trouble with the syntax.
>
> I need to work hard to solidify how to put it together in a real coded
> situation.
>
> OTH, This code posted below makes more sense to my brain. I was on this
> track earlier, but digressed into the above approach - which is
> probably more
> elegant, but difficult for me to see how to do in practice.
>
> deb
>
>
>
> R. Joseph Newton <[EMAIL PROTECTED]> had this to say,
>
> > Deb wrote:
> >
> > > Hi Guys,
> > >
> > > I have an array in which each element is a line commandline
> data. It looks
> > > something like this -
> > >
> > > @Array contains lines:
> > >
> > > post1: -r [EMAIL PROTECTED] -x cat-100 -h post1
> > > post2: -x tel -h post2
> > > post3: -h post3 -x hifi
> >
> > The getRelationships sub here has a few less typos, and the
> test stub runs well.
> >
> > #!/usr/bin/perl -w
> >
> > use strict;
> > use warnings;
> >
> > sub getRelationship($$);
> >
> > testGetRelationships();
> >
> > sub testGetRelationships {
> > my $string = "post1: -r [EMAIL PROTECTED] -x cat-100 -h post1";
> > my %relationships;
> >
> > getRelationship($string, \%relationships);
> >
> > foreach my $key (keys %relationships) {
> > print "$key:=$relationships{$key}\n";
> > }
> > }
> >
> > sub getRelationship ($$) {
> > my ($commandline, $relationships) = @_;
> > # print "$commandline\n"; #debug
> > my @commands = split /\s+-/, $commandline;
> > my $key = shift(@commands);
> > foreach (@commands) {
> > if (s/^x\s+//) {$$relationships{$key} = $_;}
> > }
> > }
> >
> >
I went through (over?) the same hurdle several years ago. I'm
happy for you that the light is beginning to burn.
However, I would advise you to get comfortable with the
'->' syntax also; _most_ 'professional' scripts
use this representation (just cruse some source code
on CPAN).
'->' is easy (again, once the light bulb shines, the
church bell chimes, the fat lady sings, ...). Here's
my trick:
Given:
$something->{$key};
I see the '->' telling me that the preceding ($something)
is a reference. Next, the {} tells me that something is
a reference to a hash and $key is the hash key. The same
syntax goes for array references:
$something->[$index];
Now, to use '->' in multi dimensions, just string them out:
$some_hash_ref->{$some_hash_key}->{$another_hash_key}->[$array_index];
Read right to left as:
The value of element number $array_index in an array referenced by
the key $another_hash_key in a hash referenced by the key
$some_hash_key in a hash referenced by $some_hash_ref!!!
Easy, yeah?
Oh well, keep on trucking'
Aloha => Beau;
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