@{ $hash{$_} } = sort{ $b->[1] <=> $a->[1] } @{ $hash{$_} } for keys %hash;; pp \%hash;; { 1 => [[26, 27, 28], [16, 17, 18], [6, 7, 8], [1, 2, 3]], 2 => [[27, 28, 29], [17, 18, 19], [7, 8, 9], [2, 3, 4]], 3 => [[28, 29, 30], [18, 19, 20], [8, 9, 10], [3, 4, 5]], 4 => [[29, 30, 31], [19, 20, 21], [9, 10, 11], [4, 5, 6]], }