use Data::Dumper;

@a = {{1, 2, 3}, {4, 5, 6}, {2, 4, 8}};
@b = ((1, 2, 3), (4, 5, 6), (2, 4, 8));
$a = [[1, 2, 3], [4, 5, 6], [2, 4, 8]];

print Dumper(\@a);
print Dumper(\@b);
print Dumper($a);

##</code><code>##

$a = [[1, 2, 3], [4, 5, 6], [2, 4, 8]];
@$a = sort { $a->[0] <=> $b->[0] } @$a;