update: the indented block is irrelevant now, with the update in the OP
Your examples are not equivalent. Your "if" case should look something like this: 
my $number = do {
  if ($logical_test) { 
    $value 
  } 
  else { 
    0 
  }
}

[download]

Note that there is no automatic assignment of the 0 value. Doesn't make much difference here, ofcourse, but for more complicated cases its possible that those assignments have side-effects, or just take a lot of time.

Anyway, I would not recommend using ?: in very complex statements, because the ? and : tend to get drowned. But then, I would not recommend using statement modifiers in such a case either: 

$bla = $some_really_long_calculation_that / $you_just_don_t * $want_to
+_read_all_the_way_to_the_end if $something;

[download]

"What should it profit a man, if he should win a flame war, yet lose his cool?"

In reply to Re: Ternary operators: a hinderance, not a help by Joost
in thread Ternary operators: a hinderance, not a help by Tanalis

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.