It's better if you can avoid an unnecessary intermediary array, e.g. in a typical case of reading ids from the first column in a tsv file, I'd go for something like: 
my %unique;
my @ids = map
{ chop;
  my @fld = split /\t/;
  !defined(  $unique{ $fld[0] } ) && $unique{ $fld[0] }++ && $fld[0];
} <$fileHandle>;

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^M Free your mind!

In reply to Re: Unique elements in array by Moron
in thread Unique elements in array by megaurav2002

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