#/usr/bin/perl -w

use strict;

my @array1 = ('one','two','one','three','four','two','one');
my @array2 = ();
my $index;
my $in;

foreach $in (@array1) {
  push(@array2,$in) if (!grep $array2[$_] eq $in, 0 .. $#array2);
}

print "@array1\n";
print "@array2\n";
__DATA__
# the result :
one two one three four two one
one two three four
[download]

@test = grep { $X{$_}} 
map { defined $X{$_} or ($X{$_} += 1),$_ } @test;
[download]

Not that I'm all into golf, but...

    @test = do { my %s; grep { !$s{$_}++ } @test };
[download]

That's assuming you want the values in the order in which they first occur.
If that's not necessary, then you can simply use a hash as a set:

    @test = do { my %s; @s{@test} = @test; values %test };
[download]

jdporter
The 6th Rule of Perl Club is -- There is no Rule #6.

20 strokes.....

sub unique {
     #2345678901234567890
     $_{$_}++for@_;keys%_
}
@unique = unique( qw( 1 2 3 4 5 1 3 5 1 3 5 ) );
print "@unique";
__DATA__
1 2 3 4 5
[download]

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

Thanks... Excellent Performance... I am new to this site. How can i post questions to this site? Can i award points to the person who helps to solve problem. Could you pls explain your written code? Thanks a lot.

This is covered in the FAQ perlfaq.

I am not sure why, but your link did not work for me - I found www.perlfaq.com helpful, kumar's exact question can be found here.

I also could not find a solution in the perldoc.com FAQ specifically addressing this question (though I am sure it is there somewhere).

I however did find kumar's question (and answer) here on PM in our own Q/A section here.

Cheers - L~R

Update: Links point directly to solution