in reply to (Ovid) Re: Is a global variable better than repetition within variables?
in thread Is a global variable better than repetition within variables?

As of perl5.6 values() returns the actual variables and not copies. This means that you can do fancy stuff like     $_ = $prefix . $_ foreach values %hash; Actually, I'd even prefer     $hash{$_} = $prefix . $hash{$_} foreach keys %hash; over the map() approach, since as you say, there can be hundreds of them (or 18278 as in your example! ;)) and building up another list of that would be a waste. Or is there any funky optimization going on that I'm unaware of?

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Re: Re: (Ovid) Re: Is a global variable better than repetition within variables?
by blakem (Monsignor) on Jan 27, 2002 at 12:44 UTC
    Just a bit of weekend golf/obfu.... 
    s//$prefix/for values%hash;

    [download]

    -Blake

[reply]
[d/l]
      I was about to suggest that too, just for fun. But I chose not to. Didn't want to start a golf/obfu thread. :)

      Anyhow, there's a bug in your code. You need to have something as pattern. Otherwise the empty pattern magic will kick in.

      -Anomo
[reply]
        What bug are you talking about? We want the empty pattern "magic" to kick in... at least the magic where it matches the emptyness sitting infront of a string. Thats how we add the prefix to each value in the hash... 
        #!/usr/bin/perl -wT
use strict;

my $prefix = 'dog';
my %hash = map {++$;,$_} (qw(ged house ma matic),'');
print "Before:\n";
print "$_ => '$hash{$_}'\n" for keys %hash;

s//$prefix/for values%hash;   # Add the Prefix...

print "\nAfter:\n";
print "$_ => '$hash{$_}'\n" for keys %hash;

__END__

Before:
1 => 'ged'
2 => 'house'
3 => 'ma'
4 => 'matic'
5 => ''

After:
1 => 'dogged'
2 => 'doghouse'
3 => 'dogma'
4 => 'dogmatic'
5 => 'dog'

        [download]

        -Blake

[reply]
[d/l]

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