my $i = 0;
again:
$array[$i] *= 2 unless $array[$i] =~ /[^0-9]/;
goto again if ++$i <= $#array;

##</code><code>##

my $i = 0;
{$array[$i] *= 2 unless $array[$i] =~ /[^0-9]/;
 redo if ++$i <= $#array;}

##</code><code>##

/[^0-9]/ or $_ *= 2 for @array;