Yes, after posting my response it hit me that your question simply didn't ask what you wanted answered.
Zaxo has it right; you probably want a hash with key/value relationship. Then you ultimately want the strings stored as keys, and the computed values as values associated with the keys. ...something like this:
use strict;
use warnings;
my %strings;
# Set up some example key/value relationships. Your method
# for populating the hash will be more complex, but isn't
# defined in the question.
$strings{"Here is one string"} = 233;
$strings{"Here is another string"} = 151;
$strings{"Here is yet another"} = 322;
print map{ "$_ = $strings{$_}\n" }
sort{ $strings{$b} <=> $strings{$a} }
keys %strings;
