Do you have a favorite "Accessing Data in Nested Structures for Complete Idiots" tutorial

Bad question. Don't access data in a nested structure. Access the data you have at hand.

One would access the countries in a list of counties as follows: 

for my $country_name (keys(%$countries)) {
   my $country = $countries->{$country_name};
   ...
}

[download]

One would access the provinces in a list of provinces as follows: 

for my $province_name (keys(%$provinces)) {
   my $province = $provinces->{$province_name};
   ...
}

[download]

Maybe $provinces is the same as $country or $country->{provinces} or $country->get_provinces(). Does it matter? No. 

for my $country_name (keys(%$countries)) {
   my $country = $countries->{$country_name};

   my $provinces = $country->{provinces};

   for my $province_name (keys(%$provinces)) {
      my $province = $provinces->{$province_name};
      ...
   }
}

[download]

In reply to Re: Nested Data Structures for Dummies? by ikegami
in thread Nested Data Structures for Dummies? by jedikaiti

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.