Get only unique values into array

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi there Monks!
I am trying to check if this particular value already is in this array to avoid having duplicated values in it.
I just can't get this code to work.
I have this code sample that I hope shows what and where I am having issues.

This is the first array:

…
my @loop_names = (); 
foreach my $row (@{$names_data}) {

   my %row_data;
   
   $row_data{NAMES} = $row->{NAMES} || '';

   push(@loop_names, \%row_data);
   
}
# Dumper of @loop_names;
=code
 $VAR1 = {
           'NAMES' => 'John Doe'
         };
 $VAR2 = {
           'NAMES' => 'Mary Lou'
         }
=cut
[download]

This is from the second array:

my @loop_addr = ();
 foreach my $row (@{$all_party_id_data}) {

   my %row_data;

   $row_data{FULL_NAME} = $row->{FULL_NAME} || '';
   $row_data{ADDR}      = $row->{ADDR}      || '';
   $row_data{ZIP}       = $row->{ZIP}       || '';

   warn Dumper $row_data{FULL_NAME}; # it will get "Mary Lou"

   # I just want @loop_names to have what is unique
   @loop_names = map /$row_data{FULL_NAME}/ ? () : $_, @loop_names;
   
   $row_data{N_DATA} = \@loop_names;

   push(@loop_addr, \%row_data);
}

# Dumper of @loop_addr
=code
$VAR1 = {

    'FULL_NAME' => 'Mary Lou',
    'ADDR' => '100 - Main Street',
    'ZIP' => '12345',
    'EMAIL_DATA' => [
                      {
                        'NAMES' => 'John Doe'
                      },
                      {
                        'NAMES' => 'Mary Lou' # this shouldn't be here
+ 
                      }
                    ],

        };
=cut
[download]

I would like this array to only have this at the end, because “John Doe” is the only unique value:

$VAR1 = {

    'FULL_NAME' => 'Mary Lou',
    'ADDR' => '100 - Main Street',
    'ZIP' => '12345',
    'EMAIL_DATA' => [
                      {
                        'NAMES' => 'John Doe'
                      },
                    ],

        };
[download]

Thanks for looking!

Comment on Get only unique values into array Select or Download Code

Replies are listed 'Best First'.
Re: Get only unique values into array by pme (Monsignor) on Jan 28, 2015 at 19:53 UTC
You can do this way: `my %h = map { $_, 1 } @arr; my @uniq_arr = keys %h;` [download] or module List::MoreUtils can be used.	[reply] [d/l]
Re: Get only unique values into array by stonecolddevin (Parson) on Jan 28, 2015 at 23:23 UTC
Take a look at Set::Scalar. Three thousand years of beautiful tradition, from Moses to Sandy Koufax, you're god damn right I'm living in the fucking past	[reply]
Re: Get only unique values into array by Anonymous Monk on Jan 28, 2015 at 19:59 UTC
`@loop_names = map /$row_data{FULL_NAME}/ ? () : $_, @loop_names;` [download] @loop_names doesn't contain strings, it has hashrefs, which stringify to something useless. So that's not going to work. Also, grep is used for filtering elements of a list.	[reply] [d/l]
Re: Get only unique values into array by BillKSmith (Monsignor) on Jan 28, 2015 at 23:55 UTC
Checkout the function uniq in List::MoreUtils. Bill	[reply]
Re: Get only unique values into array by Laurent_R (Canon) on Jan 28, 2015 at 19:49 UTC
Whenever you think about unique value, think hash. In other terms, use a hash to check whether the value has already been seen. Je suis Charlie.	[reply]
Re^2: Get only unique values into array by Laurent_R (Canon) on Jan 28, 2015 at 20:01 UTC
Hum, it looks like what you are asking is more complicated than what I originally understood. And I am not sure I do understand what your are asking... Je suis Charlie.	[reply]
Re: Get only unique values into array by poj (Abbot) on Jan 28, 2015 at 19:53 UTC
`# I just want @loop_names to have what is unique # add --------------- @loop_names = map { $_->{'NAMES'}=~/$row_data{FULL_NAME}/ ? () : $_ } @loop_names;` [download] Are you sure you want to overwrite `@loop_names` ? poj	[reply] [d/l] [select]
Re^2: Get only unique values into array by Anonymous Monk on Jan 28, 2015 at 20:05 UTC
Yes, as long as it will only have unique values in there. I don't see any other way.	[reply]