Re^6: Get just the unique value

[Anonymous Monk]

I tested, none of them work unfortunately, I will look also where.

[CountOrlok]

Maybe if you gave us the desired output...

[Anonymous Monk]

Sure, the end result is that $data only holds the unique values: From this:

my $data = [
   {
 
     'type' => 'Paper'
   },
   {

     'type' => 'Paper'
   },
   {

     'type' => 'Plastic'
   },   {

     'type' => 'Plastic'
   },   {

     'type' => 'Plastic'
   },   {

     'type' => 'Plastic'
   },
   {

     'type' => 'Cotton'
   },
   {

     'type' => 'Cotton'
   },
   {

     'type' => 'Cotton'
   },
   {

     'type' => 'Cotton'
   },
   {

     'type' => 'Cotton'
   },
{

     'type' => 'Paper'
   },
{

     'type' => 'Paper'
   },
{

     'type' => 'Paper'
   },
{

     'type' => 'Paper'
   },
{

     'type' => 'Paper'
   },

];

To that:

 $data = [
   {
 
     'type' => 'Paper'
   },
  {

     'type' => 'Plastic'
   },
   {

     'type' => 'Cotton'
   },
 
];

[CountOrlok]

hdb's code does exactly that, albeit sorted.

[hdb]

How about this?

my %types;
my $res;
foreach my $entry (@$data) {
    push @$res, $entry unless $types{$entry->{"type"}}++;
}

print Dumper $res;

[hdb]

Or this without helper hash?

my $res;
foreach my $entry (@$data) {
    push @$res, $entry unless grep { $_->{"type"} eq $entry->{"type"} 
+} @$res;
}

print Dumper $res;