Well, first off, by putting parens around "vodka=(\d{2})", you've created another capture, but the approach that might have been "correct" also doesn't work: 
my $re = qr/beer=(\d{2}).*(?:vodka=(\d{2}))?.*chips=(\d{3})/;

[download]
That "matches" both strings, but doesn't capture the number that follows "vodka" in the first string. Sorry, but I can't explain why.

So I'd be inclined to take a different approach: 

#!/usr/bin/perl

use strict;
use warnings;

my @strs = (
    "beer=10&otherstuff&vodka=20&otherstuff&chips=100",
    "beer=10&otherstuff&juice=20&otherstuff&chips=100"
);

my @targets = qw/beer vodka chips/;

for ( @strs ) {
    my @matched;
    for my $target ( @targets ) {
        push @matched, $1 if ( /$target=(\d+)/ );
    }
    if ( @matched ) {
        print "matched: @matched\n";
    }
}

[download]
UPDATE: Here's a variant on that approach, which I think is closer to what your own snippet would actually do if it worked (in case that's really what you want): 
my @targets = qw/beer=(\d{2}) (vodka=(\d{2})) chips=(\d{3})/;

for ( @strs ) {
    my @matched;
    for my $target ( @targets ) {
        push @matched, ( /$target/ );
    }
    if ( @matched ) {
        print "matched: @matched\n";
    }
}

[download]

In reply to Re^3: Likely trivial regex question by graff
in thread Likely trivial regex question by moodywoody

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • 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! —
  • 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:
    & &amp;
    < &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.