Let's Add Some Spice

[Aaron Jensen]

It's time to spice up the mailing list.

I have a question about some code I've encountered in
Lincoln Stein's "Official Guide to Programming with CGI.pm"
page 71. (Don't worry, my question isn't about CGI.)

Here is the code:
0  #! /usr/bin/perl
1
2  # script: loan.cgi
3  use CGI qw/:standard :html3/;
4 
5  # this defines the contents of the fill out forms
6  # on each page
7  @Pages = ('Personal Information','References',
8 	'Assets','Review','Confirmation');
9  %FIELDS = (
10   'Personal Information'=>
11      ['Name','Address','Telephone','Fax],
12   'References'=>
13      ['Personal References 1','Personal References 2'],
14   'Assets'=>
15      ['Savings Account','Home','Car']
16 );
17
18 # accumlate the field names into %ALL_FIELDS:
19 foreach(values %FIELDS){
20     grep(%ALL_FIELDS{$_}++, @$_);
21 }

My question is, what is happening on lines 19 - 21?  I've
stared at it and stared at it, looked in Perl books,
experimented, and have a very fuzzy approximation/guess of
what is going on.  I know what the result is, just not how
that result is acheived.  How can clear things up for me?

-- 
=-=-=-=-=-=-=-=-=-=-=-=
Aaron Jensen         
atjensen at home.com      
Visual Prose Web Design  
www.proseweb.com      
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TIMTOWTDI