morgon:   Further to Corion's post:

[Corion]: The match runs to completion before the map even starts.

At the time your map runs, $1 and $2 are what they are at the end of the global match.

Here's an instrumented version of the OPed code to better (I hope) show what's happening:

c:\@Work\Perl\monks>perl -wMstrict -le
"use Data::Dumper;
 ;;
 my $s = \"1 A\n2 B\n33 foo\n\";
 ;;
 my %h =
   map { print qq{in map: \$_ '$_'  \$1 '$1'  \$2 '$2'};  $1 => $2; }
   $s =~ /(\d+)\s+(\S+)/mg
   ;
 print Dumper(\%h);
"
in map: $_ '1'  $1 '33'  $2 'foo'
in map: $_ 'A'  $1 '33'  $2 'foo'
in map: $_ '2'  $1 '33'  $2 'foo'
in map: $_ 'B'  $1 '33'  $2 'foo'
in map: $_ '33'  $1 '33'  $2 'foo'
in map: $_ 'foo'  $1 '33'  $2 'foo'
$VAR1 = {
          '33' => 'foo'
        };
[download]

(Note that this example doesn't take into account the revised data format specification suggested here. :)

---

---

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.