my @array = @{ $key };
print join ",", @array;

[download]

should be 

my @array = @{ $reverse_translation{key} };
print join ",", @array;

[download]

But that wastefully copies the array. Just work with the array reference: 

my $array = $reverse_translation{key};
print join ",", @$array;

[download]

Update: Oops, I missed the fact that you reversed the keys and values.

While the above does solve a problem, you are also running afoul of the restriction that hash keys (for untied hashes) can only be strings. When you attempted to use an array reference as a key, a string representation of the array reference was used as the key rather than the array reference itself. So when you tried to deference the keys, you were trying to dereference a string.

What are you trying to accomplish by reversing the hash? Would the following do? 

foreach my $key (keys %translation) {
   print("$key: ");
   print(join(",", @{ $translation{$key} }));
   print("\n");
}

[download]

In reply to Re: Problem de-referencing a variable by ikegami
in thread Problem de-referencing a variable by Anonymous Monk

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.