I like toolic's 2-D hash suggestion. However, sometimes I use just a 1-D hash. Depending upon what you are doing, this can lead to some simplifications, e.g. printing a HoH takes 2 foreach loops, a simple 1-D hash just takes one. On the other hand some operations may become more complicated. I'm just presenting another option that sometimes is a good choice. Mileage varies!

The relevant line to change n toolic's code is this one:

    #$hash{$row}{$cols[$i+1]} = $vals[$i]; #toolic's
    $hash{"$row,$cols[$i+1]"} = $vals[$i]; #1-D version

[download]
Now, 
foreach (sort keys %hash)
{
   print "$_  $hash{$_}\n";
}
__END__
prints:
aaa,bar  456
aaa,baz  789
aaa,foo  123
bbb,bar  654
bbb,baz  321
bbb,foo  987

[download]
The pitfall in this method is that some character or sequence of characters that cannot be in the row or column header names should be used to join the row,col names together. You want to guarantee that running together any row,col results in a unique name. This is usually not a problem and "," is often a good choice.

Have fun!

In reply to Re: Making a two dimensional hash with first row and column as the keys by Marshall
in thread Making a two dimensional hash with first row and column as the keys by limzz

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.