Your posted code fails compile with the error 
Missing $ on loop variable

[download]
Please make sure that when you post code, it literally replicates your issue -- see How do I post a question effectively?.

If I run the code: 

my %lengths = (
    1 => {x => 1,
          y => 2,
          z => [1,2,3],
         },
    2 => {x => 2,
          y => 3,
          z => [2,3,4],
         },
    3 => {x => 4,
          y => 5,
          z => [5,6,7],
         },
);

for my $coord (keys %lengths) {
   for (@{$lengths{$coord}{z}}) {
      print "$_\n";
   }
}

[download]
I get the output 
1
2
3
5
6
7
2
3
4

[download]
which seems to be your spec. My best guess is that you've got a typo in the code you are actually running, so that you aren't accessing the array. Try checking Data::Dumper after your loop to see if you are getting bitten by autovivification.

#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

In reply to Re: Help with array ref in hashes by kennethk
in thread Help with array ref in hashes by diyaz

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.