Variable reference

[Tad McClellan]

Par <paer_nystroem@hotmail.com> wrote:

> I have a lot of variables in the form of
> $var{$something} = "Some text";
>
> $something consists of two parts though. Ideally I would have liked it
> to be in the form of $var{$part1$part2}, but that doesn't work...
> So the really nasty looking part I've had to add is
> $something = $part1 . $part2;
>
> So my question is basically how I avoid having the above line?!

$var{ $part1 . $part2 }
or
$var{ "$part1$part2" }


--
Tad McClellan SGML consulting
[email]tadmc@augustmail.com[/email] Perl programming
Fort Worth, Texas

[Jeff 'japhy' Pinyan]

On 21 Jul 2003, Par wrote:

>$var{$something} = "Some text";
>
>$something consists of two parts though. Ideally I would have liked it
>to be in the form of $var{$part1$part2}, but that doesn't work...
>So the really nasty looking part I've had to add is
>$something = $part1 . $part2;
>
>So my question is basically how I avoid having the above line?!

Just do

$var{$part1 . $part2}

or

$var{"$part1$part2"}

--
Jeff Pinyan RPI Acacia Brother #734 2003 Rush Chairman
"And I vos head of Gestapo for ten | Michael Palin (as Heinrich Bimmler)
years. Ah! Five years! Nein! No! | in: The North Minehead Bye-Election
Oh. Was NOT head of Gestapo AT ALL!" | (Monty Python's Flying Circus)

[Shawn Corey]

Hi,

You should use $var{ $a, $b } = "Some text";
The key would be $a . $; . $b
$; is set to \034 but you can change it to any character you like.

This is an example to print the keys and values.
for my $key ( keys %var ){
my ( $a, $b ) split /$;/, $key;
print "key $a, $b has value $var{ $key }\n"
}

Jeff 'japhy' Pinyan wrote:

> On 21 Jul 2003, Par wrote:
>
>

>>$var{$something} = "Some text";
>>
>>$something consists of two parts though. Ideally I would have liked it
>>to be in the form of $var{$part1$part2}, but that doesn't work...
>>So the really nasty looking part I've had to add is
>>$something = $part1 . $part2;
>>
>>So my question is basically how I avoid having the above line?!

>
>
> Just do
>
> $var{$part1 . $part2}
>
> or
>
> $var{"$part1$part2"}
>

[Tassilo v. Parseval]

[ Please don't top-post;
your reply should come after the original text ]

Also sprach Shawn Corey:

> You should use $var{ $a, $b } = "Some text";
> The key would be $a . $; . $b
> $; is set to \034 but you can change it to any character you like.
>
> This is an example to print the keys and values.
> for my $key ( keys %var ){
> my ( $a, $b ) split /$;/, $key;
> print "key $a, $b has value $var{ $key }\n"
> }

While the above is certainly right from a technical standpoint, I
stumbled over your first sentence:

> You should use $var{ $a, $b } = "Some text";

I think this misses the point of the OP. He was essentially just asking
how to concatenate two strings to one hash-key. Using $hash{ LIST }
however is a Perl4ism. In a time when references weren't yet there, Perl
needed a way to work with multidimensional data-structures. Joining the
elements of the list together with $; was therefore just a work-around.
Nowadays fortunately perl knows about references and thus the
multidimensional array emulation is no longer needed.

Tassilo
--
$_=q#",}])!JAPH!qq(tsuJ[{@"tnirp}3..0}_$;//::niam/s~=)]3[))_$-3(rellac(=_$({
pam{rekcahbus})(rekcah{lrePbus})(lreP{rehtonabus}) !JAPH!qq(rehtona{tsuJbus#;
$_=reverse,s+(?<=sub).+q#q!'"qq.\t$&."'!#+sexisexi ixesixeseg;y~\n~~dddd;eval

[Jeff 'japhy' Pinyan]

On 21 Jul 2003, Tassilo v. Parseval wrote:

>> You should use $var{ $a, $b } = "Some text";
>> The key would be $a . $; . $b
>> $; is set to \034 but you can change it to any character you like.

>
>I think this misses the point of the OP. He was essentially just asking
>how to concatenate two strings to one hash-key. Using $hash{ LIST }
>however is a Perl4ism. In a time when references weren't yet there, Perl
>needed a way to work with multidimensional data-structures. Joining the
>elements of the list together with $; was therefore just a work-around.
>Nowadays fortunately perl knows about references and thus the
>multidimensional array emulation is no longer needed.

Although, as was stated, you could set $; to "", and thereby make it work
like the OP wanted. ;)

--
Jeff Pinyan RPI Acacia Brother #734 2003 Rush Chairman
"And I vos head of Gestapo for ten | Michael Palin (as Heinrich Bimmler)
years. Ah! Five years! Nein! No! | in: The North Minehead Bye-Election
Oh. Was NOT head of Gestapo AT ALL!" | (Monty Python's Flying Circus)