Re: Homework help

I found two problems:

You're printing $_, but $r contains what you want to print.

You should uppercase the input (using uc()). Hash lookups are case-sensitive.

I also have two recommendations:

It would make more sense if if ($word eq 'q'){ appeared before the split.

Something's really odd with your foreach+grep. In fact, there's no need for a foreach at all. Get rid of the foreach loops and use just @result = grep {defined $_} @pay{@word}; (which simplifies to @result = grep defined, @pay{@word};). You'd be smart if you went and reread some examples using grep, and make sure you know what @hash{list} returns.

Now you just have to sum up the elements of @result with something like my $sum = 0; $sum += $_ foreach @result;.

You could even remove the grep, replace it with a for/foreach loop that does both the validation and the summing. In fact, that's probably a good idea.

Here's how I'd do it:

my %scores = (
   map { $_ =>  1 } qw( A E I L N O R S T U ),
   map { $_ =>  2 } qw( B D G               ),
   map { $_ =>  3 } qw( C M P               ),
   map { $_ =>  4 } qw( F H V W Y           ),
   map { $_ =>  5 } qw( K                   ),
   map { $_ =>  8 } qw( J X                 ),
   map { $_ => 10 } qw( Q Z                 ),
);

print("Find the Scrabble value of a word.$/$/");

for (;;) {
   print("Enter a word (or just Enter to quit): ");
   local $_ = <STDIN>;
   last unless defined;
   chomp;
   last unless length;
   $_ = uc($_);

   my $sum = 0;
   $sum += $scores{$1} while (/([A-Z])/g);

   print("Scrabble value: $sum$/$/");
}
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Re^2: Homework help by Your Mother (Archbishop) on Oct 30, 2004 at 07:04 UTC
I was playing around with this and noticed a harmless but problematic side-effect of the way you construct the hash. `%scores = ( map { $_ => 1 } qw( A E I L N O R S T U ), map { $_ => 2 } qw( B D G ), map { $_ => 3 } qw( C M P ), map { $_ => 4 } qw( F H V W Y ), map { $_ => 5 } qw( K ), map { $_ => 8 } qw( J X ), map { $_ => 10 } qw( Q Z ), ); print join($", sort keys %scores), $/; __END__ 10 2 3 4 5 8 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z` [download] Since you're filtering for letters, the numbers don't get picked up, but the maps are having a side-effect mapping of the other maps below them. Parens around the maps seems to fix it. I also learned something from your example. I would have predicted that the `last unless defined` would not work right on empty input b/c $_ still contains a "\n" which would be defined. I would have been wrong.	[reply] [d/l]
Re^3: Homework help by ikegami (Patriarch) on Oct 30, 2004 at 17:55 UTC
I would have predicted that the `last unless defined` would not work right on empty input b/c $_ still contains a "\n" It doesn't work on empty input. It works on eof/error. It's there to prevent the next two lines from giving "undefined value" warnings under `use warnings`. The `last unless length` that follows is what detects the empty string (since chomp removed the "\n" by then).	[reply] [d/l] [select]
Re^2: Homework help by !1 (Hermit) on Oct 30, 2004 at 22:16 UTC
Wow, your %scores isn't defined correctly at all. # perl -l my %scores = ( map { $_ => 1 } qw( A E I L N O R S T U ), map { $_ => 2 } qw( B D G ), map { $_ => 3 } qw( C M P ), map { $_ => 4 } qw( F H V W Y ), map { $_ => 5 } qw( K ), map { $_ => 8 } qw( J X ), map { $_ => 10 } qw( Q Z ), ); print "$_ => $scores{$_}" for keys %scores; __END__ S => 1 T => 1 N => 1 K => 1 Y => 1 2 => 1 E => 1 Z => 1 J => 1 W => 1 B => 1 H => 1 D => 1 I => 1 10 => 1 G => 1 U => 1 F => 1 V => 1 Q => 1 M => 1 C => 1 L => 1 A => 1 O => 1 3 => 1 X => 1 P => 1 8 => 1 4 => 1 R => 1 5 => 1 [download] Perhaps this is a good time for parentheses? `my %scores = ( map( { $_ => 1 } qw( A E I L N O R S T U ) ), map( { $_ => 2 } qw( B D G ) ), map( { $_ => 3 } qw( C M P ) ), map( { $_ => 4 } qw( F H V W Y ) ), map( { $_ => 5 } qw( K ) ), map( { $_ => 8 } qw( J X ) ), map( { $_ => 10 } qw( Q Z ) ), ); print "$_ => $scores{$_}" for keys %scores; __END__` [download]	[reply] [d/l] [select]


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