Question

I have an array in Perl:

my @my_array = ('one','two','three','two','three'); 

How do I remove the duplicates from the array?

Answer 1

You can do something like this as demonstrated in perlfaq4:

sub uniq {     my %seen;     grep !$seen{$_}++, @_; }  my @array = qw(one two three two three); my @filtered = uniq(@array);  print "@filtered\n"; 

Outputs:

one two three 

If you are aiming for universality, you should take a look at the uniq function. It is included in the core module List::Util as of Perl v5.26.0 (for older versions, use List::MoreUtils). This function differs from the above sketch in that it treats undef as a separate value, different from '', and does not issue a warning.