You have an off-by-one error here.

$ perl -MData::Dumper -e '
> my @array = (1, 2, 3, 4, 5, 6, 7, 8);
> my @new_array = map{ [$array[2 * $_ - 1], $array[2 * $_]] } 1 .. @ar
+ray/2;
-> print Dumper(\@new_array);'
$VAR1 = [
          [
            2,
            3
          ],
          [
            4,
            5
          ],
          [
            6,
            7
          ],
          [
            8,
            undef
          ]
        ];
$

[download]

This works.

$ perl -MData::Dumper -e '
> my @array = (1, 2, 3, 4, 5, 6, 7, 8);
> my @new_array = map{ [$array[2 * $_], $array[2 * $_ + 1]] } 0 .. $#a
+rray/2;
-> print Dumper(\@new_array);'
$VAR1 = [
          [
            1,
            2
          ],
          [
            3,
            4
          ],
          [
            5,
            6
          ],
          [
            7,
            8
          ]
        ];
$

[download]

Cheers,

JohnGG

In reply to Re^2: Arrays of Arrays by johngg
in thread Arrays of Arrays by perl_junior_121

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.