#!/usr/bin/perl

use strict;
use warnings;
use diagnostics;

my @array = (3, 4, 1, 4, 7, 7, 4, 1, 3, 8);

my %unordered;
@unordered{@array} = undef; # array context takes values of array in unordered array which is a hash so keys cannot be same and their values are undef;

foreach my $key (keys %unordered)
{
	print "Unordered: $key \n";
}

my %seen;
my @ordered;

foreach my $element (@array)
{
	if( not $seen{$element}++ )
	{
		push @ordered, $element;
	}
}

foreach my $element (@ordered)
{
	print "Ordered: $element \n";
}