Re: Grouping Objects by Attribute

some untested pseudo-code ;) to get you started...

my %monks_by_level;

for my $monk ( @array_of_monks )
{
  my $level = $monk->level(); # or ->{level} or whatever...
  push @{ $monks_by_level{$level} }, $monk;
}

for my $level ( keys %monks_by_level )
{
  print "doing $level...\";
  callToPrayer( $monks_by_level{$level} );
}

sub callToPrayer
{
  my ($monks) = @_;

  for my $monk ( @$monks )
  {
    print "$monk->name() here!\n";
  }
}
[download]

--
edan

Comment on Re: Grouping Objects by Attribute Download Code

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Re^2: Grouping Objects by Attribute by loris (Hermit) on Nov 01, 2004 at 09:47 UTC
Thanks, edan, that did the trick. However, I don't quite get the bit `@{ $monks_by_level{$level} }` I understand this to mean that the `$monks_by_level{$level}` is the value of the hash for the key `$level` and that the `@{ ... }` around it automagically makes this value an array. Is this right? loris	[reply] [d/l] [select]
Re^3: Grouping Objects by Attribute by edan (Curate) on Nov 01, 2004 at 10:14 UTC
You're right, you just need a bit of terminology thrown in there. `$monks_by_level{$level}` is an `array reference (see perlref for details)` and `@{ }` is how we dereference an array reference, so that we can use it as an array. You could also dereference individual scalars in the array using syntax such as `$monks_by_level{$level}[0]`. -- edan	[reply]