Populating an Array of Referenced Values

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hello Fellow Monks. I want to populate an array of referenced values; (I believe that is the correct term, please forgive me if it is not). My code attempt (chunk of code) is shown below:

#!/usr/bin/perl -w
use strict;

my @envars;

$envars[0]->{value}="23";
$envars[0]->{description}="temperature in Celsius";
$envars[1]->{value}="56";
$envars[1]->{description}="relative humidity in \%";
$envars[2]->{value}="1008.1";
$envars[2]->{description}="pressure in millibars \%";
$envars[3]->{value}="4";
$envars[3]->{description}="dewpoint in degrees Celsius";
$envars[4]->{value}="344";
$envars[4]->{description}="total column ozone in Dobson Units";
[download]

Is there a more efficicent/streamlined way of doing this?
Perhaps a near one liner?
Any help/insight provided is greatly appreciated. Thanks!

Comment on Populating an Array of Referenced Values Download Code

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Re: Populating an Array of Referenced Values by duff (Parson) on Feb 02, 2004 at 20:50 UTC
Depends on many things as to how "efficient" you can get . Here's one possibility: `my @envars; push @envars,{ value => 23, description => 'temperature in Celsius' }, { value => 56, description => 'relative humidity in %' } +, { value => 1008.1, description => 'pressure in millibars +' }, { value => 4, description => 'dewpoint in degrees Celsiu +s' }, { value => 344, description => 'total column ozone in Do +bson Units' };` [download] You could do better by not repeating the text "value" and "description" several times. `# say you've got 2 parallel arrays @values and @descriptions my @envars = map({ value => $values[$_], description => $descriptions[ +$_] }, 0..$#values);` [download] Or perhaps you really want to just push them onto the array rather than clobbering it each time... `# Same assumption as before ... for my $i (0..$#values) { push @envars, { value => $values[$i], description => $descriptions[$ +i] }; }` [download] duff	[reply] [d/l] [select]
Re: Populating an Array of Referenced Values by Not_a_Number (Prior) on Feb 02, 2004 at 21:32 UTC
Perhaps you are looking for an over-complicated data structure. But please ignore this if it's not applicable. What I would do with the data you have shown us is create a simple hash, with the keys equivalent to your 'description' and the values, er.. equivalent to your 'value's: `use warnings; use strict; my @fields = ( 'temperature in Celsius', 'relative humidity in %', 'pressure in millibars %', 'dewpoint in degrees Celsius', 'total column ozone in Dobson Units', ); my @values = qw ( 23 56 1008.1 4 344 ); my %hash; @hash{@fields} = @values; # Print the whole thing: print "$_: $hash{$_}\n" for keys %hash; # Print one element: print $hash{'temperature in Celsius'};` [download] But perhaps you have a reason for making it more complicated? dave	[reply] [d/l]
Re: Populating an Array of Referenced Values by Enlil (Parson) on Feb 02, 2004 at 20:51 UTC
Take a look at perldsc (Arrays of Hashes). -enlil	[reply]
Re: Populating an Array of Referenced Values by Limbic~Region (Chancellor) on Feb 02, 2004 at 20:53 UTC
Anonymous Monk, Each element of the array points to an anonymous hash containing exactly two keys. I doubt you would prefer this syntax any better: `@{$envars[0]}{qw(value description)} = ('23' , 'temperature in Celsius +'); @{$envars[1]}{qw(value description)} = ('56' , 'relative humidity in % +');` [download] If you can, you might want to change to a hash of arrays: `@{ $envars{value} } = qw(23 56 1008.1 4 344); @{ $envars{description} } = ( 'temperature in Celsius', 'relative humidity in %', 'pressure in millibars %', 'dwpoint in degrees Celsius', 'total column ozone in Dobson Units' );` [download] Cheers - L~R	[reply] [d/l] [select]