Fellow monks:
First of all, the code here actually works. But can it be done better? (You might want to skip this node unless you're a golfer or efficiency nut).

Desc: each database record contains a name with their city and state. There can be multiple records with the same state and city; e.g., 10 in Texas with 5 in Dallas, 2 in Fort Worth, 3 in Waco, etc. At this point in the script, I only want to show each unique state with unique city names underneath; e.g., 1 heading for Texas, with 1 listing each for Dallas, Fort Worth, and Waco under it. You know the drill.

Like I said, it works. But code feels amateurish, like using the $temp_ variables to hold the first instance of a state or city. I've read nodes here on PM using grep and map to normalize arrays, and checked the Perlfaqs, but not sure how those methods would work with the hash or would be any cleaner. Comments? Ideas? Tee-time? Thanks.
   while (@data = $sth->fetchrow_array()) {

      if ($data[1] ne $tempstate) {
         undef (@cities);
         push (@cities, $data[0]);
         $states{$data[1]} = [ @cities ];
         $tempstate = $data[1];
         $tempcity = $data[0];
         
      } elsif ($data[0] ne $tempcity) {   
         push (@cities, $data[0]);
         $states{$tempstate} =  [ @cities ];      
         $tempcity = $data[0];
      }
  
 }

[download]
For the entire script: 
#!/usr/bin/perl

print "Content-type: text/html\n\n";

use warnings;                        
use CGI::Carp qw(fatalsToBrowser);  
use strict;

my ($dbh, $sth, $stmt, $tempstate, $tempcity, %states, @data, @cities,
+ $city, $x);

   &dbconnect;                     #connect to database subroutine

   $stmt = "SELECT city, state, country FROM sponsor ORDER BY country,
+ state, city";
   $sth = $dbh->prepare($stmt) or die "prepare: $stmt: $DBI::errstr";
   $sth->execute() or die"execute: $stmt: $DBI::errstr";
   
   while (@data = $sth->fetchrow_array()) {

      if ($data[1] ne $tempstate) {
         @cities = "";
         push (@cities, $data[0]);
         $states{$data[1]} = [ @cities ];
         $tempstate = $data[1];
         $tempcity = $data[0];
         
      } elsif ($data[0] ne $tempcity) {   
         push (@cities, $data[0]);
         $states{$tempstate} =  [ @cities ];      
         $tempcity = $data[0];
      }
  
 }   

   
   for my $state ( keys %states ) {
      print "$state:<br />";
      for my $i (1..$#{ $states{$state} } ) {
         print "$i = $states{$state}[$i]<br />";
      }   
   }
                                             
   $sth->finish();
   $dbh->disconnect();

[download]

—Brad
"A little yeast leavens the whole dough."

In reply to Better code for normalizing a list for a HoA? by bradcathey

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