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in reply to Javascript to Perl = fail

sub isprime($) { my $num = $_[1]; $primer = 1; $ValidChars = "2357"; $str = $num; if (index($ValidChars, ord(substr $str, 0, 1)) == 1) { $primer = 0; } return $primer; }
That returns 1 unless the first character of the first argument (assuming you fix the already noticed error regarding $_[1]) equals 3. I think you are calling isprime only with single digit numbers, and want to return if the digit is a prime number. I'd write that as:
sub isprime {$_[0] =~ /^[2357]$/}
although I would fix the name. Or just inline the test -- that's a lot clearer than any name I can think of.
if (($n != 1) && ($n != 0)) { if (isprime($n)) { $prime += $n; } if (!isprime($n)) { $comp += $n; } }
Too many ifs, and too many calls to isprime. I'd write that as:
if ($n =~ /^[2357]$/) { $prime += $n; } elsif ($n !~ /^[01]$/) { $comp += $n; }
Or, when I'm in the mood for something funky, as a ternary returning an lvalue.
$text.length
That should be spelled length($text).