Deleting repeating array elements

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

Part of the problem I am stuck in is to use an array element as a hashkey, I managed to create this array, however, the elements in the array are repeating, I want to modify the code such that for every element in @continents there is only one single occurrence within the array itself (purging out repeating elements).

My plan is to use an array element as a key in a hash and this hash would hold an anonymous array member corresponding to a country (Would work on that afterwards).

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

my @continents;
my($key, $value);
while(<DATA>){
        chomp;
        my($key, $val)=split /:/;
        push @continents,$key;
        }
print "@continents\n";


__DATA__
Europe:Germany
Europe:France
Asia:India
Europe:Italy
Asia:Japan
Asia:Indonesia
[download]

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Comment on Deleting repeating array elements Download Code

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Re: Deleting repeating array elements by johngg (Canon) on Aug 17, 2009 at 22:46 UTC
I wonder if this is what you are aiming to do. `use strict; use warnings; use Data::Dumper; my %continents; while ( <DATA> ) { chomp; my( $continent, $country ) = split m{:}; push @{ $continents{ $continent } }, $country; } print Data::Dumper->Dumpxs( [ \ %continents ], [ qw{ *continents } ] ); __DATA__ Europe:Germany Europe:France Asia:India Europe:Italy Asia:Japan Asia:Indonesia` [download] The output. `%continents = ( 'Europe' => [ 'Germany', 'France', 'Italy' ], 'Asia' => [ 'India', 'Japan', 'Indonesia' ] );` [download] I hope I have guessed correctly and this is of some help. Cheers, JohnGG	[reply] [d/l] [select]
Re^2: Deleting repeating array elements by biohisham (Priest) on Aug 17, 2009 at 23:46 UTC
This is exactly the sort of code steps that I got in my mind, I remember having read a similar solution at some tutorials but I could not retrieve it today that I needed it, what a shame. Thanks a lot, I appreciate this :) Excellence is an Endeavor of Persistence. Chance Favors a Prepared Mind.	[reply] [d/l]
Re: Deleting repeating array elements by toolic (Bishop) on Aug 17, 2009 at 21:27 UTC
List::MoreUtils`::uniq` Categorized Questions and Answers > QandASection: arrays: How do I find if an array has duplicate elements, if so discard it? How to find and remove duplicate elements from an array?	[reply] [d/l]
Re: Deleting repeating array elements by JavaFan (Canon) on Aug 17, 2009 at 21:17 UTC
`perldoc -q duplicate` contains the answer of your question. But your code suggest you should use a hash instead of an array.	[reply]
Re: Deleting repeating array elements by bichonfrise74 (Vicar) on Aug 17, 2009 at 21:56 UTC
Consider something like this. `#!/usr/bin/perl use strict; my %continent_of; while( <DATA>) { my ($key) = (split /:/)[0]; $continent_of{$key}++; } print join "\n", sort keys %continent_of; __DATA__ Europe:Germany Europe:France Asia:India Europe:Italy Asia:Japan Asia:Indonesia` [download]	[reply] [d/l]