While working on a problem, I came across something I couldn't explain.

When asking for the size of a newly created hash, it gave me one size. But after accessing the hash, it gave a size almost 50% larger. 

#!/usr/bin/perl
use strict;
use warnings;
use Devel::Size 'total_size';

my $s = 'AAAAAAAAAAAAAAA';

my %hash = map {$s++ => 1} 1 .. 1000;

print total_size(\%hash). ' ' . keys(%hash) . "\n";

open my $fh, '>', 'j1.txt' or die $!;

for my $key (keys %hash) {
    print $fh "$key $hash{$key}\n";
}

print total_size(\%hash). ' ' . keys(%hash) . "\n";

[download]
The results of running this code was:
105248 1000
145288 1000

[download]

I'm using perl version 5.014 and the version of Devel::Size is .08.

In reply to Devel::Size reports different size after hash access by Cristoforo

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.