Greetings fellow monks,

Apologies if either of these have been answered elsewhere and I just hadn't found them ...

First, according to the documentation for the range operator "..":

In list context, it returns a list of values counting (up
by ones) from the left value to the right value.  If the
left value is greater than the right value then it returns
the empty list.
[download]

So how in the world is the code:

#!/usr/bin/perl -w

use strict;
use warnings;

my @range = ('e' .. 'd');
printf "%s\n", join(" ", @range);
[download]

Resulting in this:

e f g h i j k l m n o p q r s t u v w x y z
[download]

?

Second, with this code:

#!/usr/bin/perl -w

use strict;
use warnings;

sub letters {
    foreach my $letter ('a' .. 'c', 'd' .. 'f') {
        print " $letter";
        $letter = uc $letter;
    }
    print "\n";
}

letters();
letters();
letters();
[download]

the results are truly not what I expect(ed):

 a b c d e f
 A B C D E F
 A B C D E F
[download]

The first time through, the letters are printed in lower-case, but subsequent passes indicate the line:

    $letter = uc $letter;
[download]

has somehow modified the list.  Can that really be what has happened?

It doesn't seem to have the same effect as:

sub letters {
    foreach my $letter ('a' .. 'f') {
        print " $letter";
        $letter = uc $letter;
    }
    print "\n";
}

# Prints...
 a b c d e f
 a b c d e f
 a b c d e f
[download]

which behaves as I would have thought.

Nor does constructing the array first have the apparent aberrant outcome:

sub letters {
    my @letters = ('a' .. 'c', 'd' .. 'f');
    foreach my $letter (@letters) {
        print " $letter";
        $letter = uc $letter;
    }
    print "\n";
}

# Prints...
 a b c d e f
 a b c d e f
 a b c d e f
[download]

The results were the same both with Perl 5.8.5 on RedHat EL4.3, and Perl 5.10.0 on Windows XP.

Can anyone enlighten me?

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.