%lcase = (a..z);
@upcase = map { uc $_, $lcase{$_} } sort keys %lcase;
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Oooh. Bonus points for the obfuscated use of a hash to break out the alternate letters!

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

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

@alpha = map { $_ % 2 ? uc $alpha[$_] : $alpha[$_] } 0..25;
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"The first rule of Perl club is you don't talk about Perl club."

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

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

tachyon

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

my $word = "The quick brown fox";
$word =~ tr/acegikmoqsuwy/ACEGIKMOQSUWY/;
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simpler:
$lcase =~ s/(\w)(\w)/\l$1\u$2/g

-- stefp

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

my @mixed_case = 'a' .. 'z';
my $other_letter = 0;
$_ = uc() for grep ++$other_letter % 2, @mixed_case;
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MiNi kRaZy golf on the modulus theme:

my $i=0;
my @a = ('a'...'z');
$i++%2||($_=uc)for@a;
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I can trim one char off of that....

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

$_ = uc for @array[grep { not $_ % 2 } 0..$#array];
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@lcase = (a..z);
@mixcase = map { ($f = !$f) ? uc : lc } @lcase;
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for(97..122){
    $init = chr; $rep = uc($init);
    eval '$string =~'."s/$init/$rep/g" if $_ % 2
}
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@lcase = ('a' .. 'y');

@upcase = sub { local $_ = join '', @_; s/(.{1,2})/ ucfirst($1) /ge; s
+plit }->( @lcase );
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Of course, you could make this a stand-alone named sub if you expect to reuse it.

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

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;
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-Blake

perl -le '@l=("a".."z"); $_=join("",@l); 
  s/../\u$&/g; 
  print'
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@lcase=(a..z);
foreach $item(@lcase)
{
  if ($sw =~/1/)
  {
    push (@case,lc($item));
    $sw=0;
  }
  else
  {
    push (@case,uc($item));
    $sw=1;
  }
}
print @case;

--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--
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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";
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