This isn't necessarily the best advice, but I personally find these traversal problems really fun to solve in perl using the $_ variable. It also gives the fastest execution time. 
sub recursive_mult_by_100() {
  if (!ref) { $_ *= 100 }
  elsif (ref eq 'ARRAY') { recursive_mult_by_100 for @$_ }
  elsif (ref eq 'HASH') { recursive_mult_by_100 for values %$_ }
  else { die "Unhandled data type ".ref; }
}

recursive_mult_by_100 for $deep;

[download]

This takes advantage of the feature where Perl aliases things to $_ during a for loop, so modifying $_ modifies the underlying thing, and where ref operates on $_ by default if you don't give it a regular parameter.

I say it's not the best advice because it isn't the most readable code, nor a standard pattern that people expect. Note that the () on the function stops it from accepting parameters, which helps you avoid the mistake of calling recursive_mult_by_100($data) and getting buggy results.

In reply to Re: Recursively change perl-data-structure by NERDVANA
in thread Recursively change perl-data-structure by richard90522

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.