Re: Complex hash sorting

How can I sort the hash by any of those delimiters? I can sort $key, but that doesn't do the job. I need to be able to print the sorted hash by ANY bit of information.

Then a hash is probably not the data structure you want. Try an array of arrays instead. You know what is supposed to be stored in each field, right?

So the idea is that you put everything into a data structure like this (using the split function):

#!/usr/bin/perl
use strict;
use warnings;

# an array: 0=name, 1=number, 2=city, 3=state, 4=zip
my @customers = (
        [ 'nye, bill','39','Somehere in Cali','Colombia','12345' ],
        [ 'simpson, homer','36','Springfield', 'OR', '23456' ],
        [ 'rubble, barney','31','Bedrock','cartoon location','33456' ]
);

# set to the array field you want
my $field = '0';

my @sorted = sort { $a->[$field] cmp $b->[$field] } @customers;

map { print $_->[$field] . "\n" } @sorted;

# OUTPUT

nye, bill
rubble, barney
simpson, homer
[download]

Of course you can tweak this to print out what ever you want. This would be best as a subroutine to which you pass the sort field number, IMO.

--
Allolex

Comment on Re: Complex hash sorting Download Code

Replies are listed 'Best First'.

Re: Re: Complex hash sorting
by parv (Parson) on Feb 01, 2004 at 09:28 UTC

Also, OP, consider using constants so that you would not have to think about array order more than once. And create a hash that would store mapping from type of elements to perl comparison operators...

#!/usr/local/bin/perl

use warnings;
use strict;

use constant
  { NAME   => [ 0 , 'cmp' ]
  , NUMBER => [ 1 , '<=>' ]
  , CITY   => [ 2 , 'cmp' ]
  , STATE  => [ 3 , 'cmp' ]
  , ZIP    => [ 4 , '<=>' ] #  Assuming zip is a number
  } ;

my @customers =
  ( [ 'nye, bill','39','Somehere in Cali','Colombia','12345' ]
  , [ 'simpson, homer','36','Springfield', 'OR', '23456' ]
  , [ 'rubble, barney','31','Bedrock','cartoon location','33456' ]
  );

#  Get user input for sort order
my @criteria = (NAME , NUMBER , ZIP , STATE);

my $sort = make_sort( \@criteria );
my @sorted = sort $sort  @customers;

#my @control =
#  sort
#  {  $a->[NAME  ->[0]] cmp $b->[NAME  ->[0]]
#  || $a->[NUMBER->[0]] <=> $b->[NUMBER->[0]]
#  || $a->[ZIP   ->[0]] <=> $b->[ZIP   ->[0]]
#  || $a->[STATE ->[0]] cmp $b->[STATE ->[0]]
#  } @customers;

use Data::Dumper;
$Data::Dumper::Deepcopy = 1;
print Dumper( \@sorted
            #, \@control
            )
            ;

sub make_sort
{ my @how = @{ $_[0] };
  my $sort =
    join ' || '
      , map
          join( $_->[1]
              , q/ $a->[/ . $_->[0] . ']'
              , q/ $b->[/ . $_->[0] . ']'
              )
          , @how ; 
  return
    eval "sub { $sort ; }";
}
[download]

Above can be retrofitted for other similar structures.

Update, Feb 1, 2004: Above is another take of Fun with complex sorting... by Dave the davido.

[reply]
[d/l]


Perl: the Markov chain saw
	PerlMonks