If you want to preserve the order, use the following: 
my @array = qw( a a b c d d );

my %counts;
my @keys = grep { !($counts{$_}++) } @array;

print("$_: $counts{$_}\n")
   foreach @keys;

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In reply to Re: Summarize or Consolidate array by value? by ikegami
in thread Summarize or Consolidate array by value? by descolada

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