use strict; use warnings; use Data::Dump::Streamer; my @data = ( ['01 Jul 2007','221.6.19.196',9,19], ['01 Jul 2007','221.6.19.197',1,3], ['01 Jul 2007','221.6.19.196',12,12], ['01 Jul 2007','221.6.19.197',2,2], ['02 Jul 2007','202.119.104.22',1,1], ['02 Jul 2007','221.6.19.196',20,45], ['03 Jul 2007','202.119.104.12',1,11], ['03 Jul 2007','202.119.110.236',1,2], ['03 Jul 2007','210.29.132.9',1,2], ['03 Jul 2007','210.29.141.188',1,2], ['03 Jul 2007','221.6.19.195',3,7], ['03 Jul 2007','221.6.19.196',4,7], ['03 Jul 2007','222.192.2.213',1,0], ['03 Jul 2007','202.119.108.42',3,3], ); my %sums; $sums{$_->[0]}{a} += $_->[1], $sums{$_->[0]}{b} += $_->[2] for map {["$_->[0],$_->[1]", @{$_}[2,3]]} @data; my @result = map {[@{$_}[1, 2, 3, 4]]} sort {$a->[0] cmp $b->[0]} map {[$_, split (',', $_), @{$sums{$_}}{'a', 'b'}]} keys %sums; Dump (\@result); #### $ARRAY1 = [ [ '01 Jul 2007', '221.6.19.196', 21, 31 ], [ '01 Jul 2007', '221.6.19.197', 3, 5 ], [ '02 Jul 2007', '202.119.104.22', ( 1 ) x 2 ], [ '02 Jul 2007', '221.6.19.196', 20, 45 ], [ '03 Jul 2007', '202.119.104.12', 1, 11 ], [ '03 Jul 2007', '202.119.108.42', ( 3 ) x 2 ], [ '03 Jul 2007', '202.119.110.236', 1, 2 ], [ '03 Jul 2007', '210.29.132.9', 1, 2 ], [ '03 Jul 2007', '210.29.141.188', 1, 2 ], [ '03 Jul 2007', '221.6.19.195', 3, 7 ], [ '03 Jul 2007', '221.6.19.196', 4, 7 ], [ '03 Jul 2007', '222.192.2.213', 1, 0 ] ];