uc() every other letter

[Anonymous Monk]

How would I uppercase every other letter in the alphabet?

@lcase = (a..z);
@upcase = map { uc() } @lcase;

But I don't want to uppercase all the letters I only want: AbCdEfG

[echo]

%lcase = (a..z);
@upcase = map { uc $_, $lcase{$_} } sort keys %lcase;

[tommyw]

Oooh. Bonus points for the obfuscated use of a hash to break out the alternate letters!

[echo]

Obfuscated? You are too kind. You got me thinking though...

@upcase = map { chr(ord() ^ ((ord() & 1) << 5)) } (a..z);

[davorg]

my @alpha = ('a' .. 'z');

@alpha = map { $_ % 2 ? uc $alpha[$_] : $alpha[$_] } 0..25;

--
<http://www.dave.org.uk>

"The first rule of Perl club is you don't talk about Perl club."

[jmcnamara]

my @lcase  = ('a'..'z');
my @upcase = map { ord() % 2 ? uc() : $_ } @lcase;



jOhn
--

[tachyon]

Or with a XOR toggle:

my $t = 0;
for( a..z ){ $t ^= 1; push @ary, $t ? $_ : uc $_ }
print @ary

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

[Sifmole]

If you really want to upcase only A's, C's, E's etc. You could use the tr/// construct.

my $word = "The quick brown fox";
$word =~ tr/acegikmoqsuwy/ACEGIKMOQSUWY/;

[George_Sherston]

How about a generic solution with a regex? Turn @lcase into a string, then
$lcase =~ s/(\w{1})(\w{1})/{$1.uc$2}/eg;

§ George Sherston

[stefp]

simpler:
$lcase =~ s/(\w)(\w)/\l$1\u$2/g

-- stefp

[George_Sherston]

Smart! Every day I learn something. Hmm. And if it's short we want, one might go as far as s/(.)(.)/$1\u$2/g

§ George Sherston

[Aristotle]

my @mixed_case = 'a' .. 'z';
my $other_letter = 0;
$_ = uc() for grep ++$other_letter % 2, @mixed_case;

[virtualsue]

MiNi kRaZy golf on the modulus theme:

my $i=0;
my @a = ('a'...'z');
$i++%2||($_=uc)for@a;

[blakem]

I can trim one char off of that....

$i++%2or$_=uc for@a;

-Blake

[runrig]

Just for variety:

$_ = uc for @array[grep { not $_ % 2 } 0..$#array];

[Ven'Tatsu]

@lcase = (a..z);
@mixcase = map { ($f = !$f) ? uc : lc } @lcase;

[thunders]

I would use Sifmole's solution
but here's a fairly silly way to do it.


for(97..122){
    $init = chr; $rep = uc($init);
    eval '$string =~'."s/$init/$rep/g" if $_ % 2
}

[dkubb]

Here's one using the "magical" $| variable:

my @mixed_case = map --$| ? uc : $_, a..z;

[blakem]

Nice, why didn't I think of that...
golf + obfu + toggles = --$|

So, we have a new leader in our golf game... 17 chars

$|--or$_=uc for@a;

-Blake

[dcd]

perl -le '@l=("a".."z"); $_=join("",@l); 
  s/../\u$&/g; 
  print'

When the number of leters is even, the ucfirst /\u/ will work on pairs of numbers matched above. if the length of the string was odd, the last character could be handled as a special case.
Seeing some of the other responses leads me to think that the question was not clearly stated what kind of input, was it a mapping on a per character basis, (where tr could help) etc..

[Aitvo]

@lcase=(a..z);
foreach $item(@lcase)
{
  if ($sw =~/1/)
  {
    push (@case,lc($item));
    $sw=0;
  }
  else
  {
    push (@case,uc($item));
    $sw=1;
  }
}
print @case;

[Anonymous Monk]

this code:

--snip--
@lcase = (a..z);
@other = ();
for ($i = 0; $i <= $#lcase; $i++) {
 if ($i % 2) {
  @other[$i] = uc($lcase[$i]);
 }
 else {
  @other[$i] = $lcase[$i];
 }
}

print "lcase:";
foreach $l (@lcase) { print " $l"; }
print "\n";

print "other: ";
foreach $o (@other) { print " $o"; }
print "\n";
--snip--

gives these results:

$ perl asdsda.txt
lcase: 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
other: 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

hope that helps.

[cricket]

i'm a lousy golfer...

use strict;

my @lc = ('a'..'z');
my (@uc, $counter);

for my $letter (@lc) {
    $counter++;
    if ($counter % 2) {
    $letter = uc($letter);
    }
    push (@uc, $letter);
}

print "@uc" . "\n";