Re: hash map to give preference to 1st match

You probably want to sort the hash by fields first. Here's an example.

#!/usr/bin/perl
use strict;
use warnings;
#by davido of perlmonks

#                   Name      Sex Age   IQ      Hair     Eyes
my %hash = (   'Lisa'   => [ 'F',  6, 150, 'Blonde',  'Blue' ],
               'Homer'  => [ 'M', 40, 105,   'Bald',  'Blue' ],
               'Bart'   => [ 'M',  9, 120, 'Blonde', 'Brown' ],
               'Marge'  => [ 'F', 36, 135,   'Blue',  'Blue' ],
               'Maggie' => [ 'F',  1, 130, 'Blonde',  'Blue' ] );

# Assume that @criteria is actually obtained at runtime.
my @criteria = ( 0, 2, 3 );

my @comparisons;
my ( $sample_key, $sample_value ) = each %hash;
foreach ( @criteria ) {
   push @comparisons, "\$hash{\$a}[$_]" .
       ( $sample_value =~ /^\d+$/ ? " <=> " : " cmp " ) .
       " \$hash{\$b}[$_]";
}

my $routine = join " || ", @comparisons;
my @sorted;

eval "\@sorted = sort { $routine } keys \%hash" or die "Ick!\n$@\n";

print $_, "\n" foreach @sorted;
[download]

I'm not really a human, but I play one on earth.
Old Perl Programmer Haiku ................... flash japh

Comment on Re: hash map to give preference to 1st match Download Code

Replies are listed 'Best First'.
Re^2: hash map to give preference to 1st match by DrHyde (Prior) on Jun 28, 2011 at 10:09 UTC
For this type of sort, rather than building up a code string and `eval()`ing, you might want to use Sort::MultipleFields.	[reply] [d/l]


Perl-Sensitive Sunglasses
	PerlMonks