map 'returns' a result for each element processed. The result is the last value of the last statement in the map block and may be a list. Consider:

#!/usr/bin/perl
use strict;
use warnings;

my @lines = qw(<tag>A</tag> <TAG>B</TAG> <tag>C</tag>);

for my $expr (
    'lc',
    'lc($_), 1',
    '$_=lc($_); s/<tag>//; s/<\/tag>//; $_ => 2'
    ) {
    my @values = eval "map {$expr} \@lines";

    print join("\n   ", "map {$expr} =>", @values), "\n";
}
[download]

Prints:

map {lc} =>
   <tag>a</tag>
   <tag>b</tag>
   <tag>c</tag>
map {lc($_), 1} =>
   <tag>a</tag>
   1
   <tag>b</tag>
   1
   <tag>c</tag>
   1
map {$_=lc($_); s/<tag>//; s/<\/tag>//; $_ => 2} =>
   a
   2
   b
   2
   c
   2
[download]

That result can be a list (as shown by almut

---

---

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.