Both arrays are (different) flat arrays of items. They contain references — the same references. At least, references that point to the same thing. And if two variables hold a reference that points to the same thing, they're almost like aliases (different variables that act as if they're one and the same variable with a different name).*

What you want to investigate is what they call a deep copy or deep cloning. I recall merlyn wrote a magazine article or two about them. See UR col 30.

Also check out Storable, a standard module that includes a function for deep copying: dclone.

p.s. The difference between variables containing the same reference, and aliases, is just this: only a direct full assignment to one of the variables, will break the interconnection. Let me give an example: 

$x = { a => 1 };   # a reference
$y = $x;           # a copy of a reference points to the same thing
$y->{a}++;         # increments $x->{a}
$y->{b} = 3;       # adds a hash item $x->{b}
$y = { c => 0 };   # breaks the connection between $x and $y
$y->{c}++;         # no effect on $x

[download]

In reply to Re: Problem Defining AoA from Named AoA by bart
in thread Problem Defining AoA from Named AoA by adeirossi

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.