This is string eval and that's the reason why string eval is considered bad practice (generally).

$ cat x.pl
#!/usr/bin/perl -Tw
use strict;
use warnings;

my $x = "016";
my $y=$x * 10;
print "y=$y\n";

$y = eval( "$x * 10" );
print "string eval evalled 016 * 10 , y = $y\n";

$y = eval { $x * 10; };
print "block eval evalled 016 * 10 , y = $y\n";

$ ./x.pl 
y=160
string eval evalled 016 * 10 , y = 140
block eval evalled 016 * 10 , y = 160

[download]

Avoid string eval. The reasons why you see the numbers you do are well explained in the previous replies. Use block eval and the problem (the apparent inconsistency) disappears and you don't have to think about unexpected stringification.

In reply to Re: Leading Zeros confound eval() ? by hippo
in thread Leading Zeros confound eval() ? by misterperl

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.