Doing a quick benchmark seems to show that it is a little bit more efficient, probably because you are only having to test once. It is certainly more readable.

use strict;
use warnings;

use Benchmark q{cmpthese};

my @states;
push @states, int rand 2 for 1 .. 10000;

cmpthese(-5,
   {
      tirwhan    => sub
         {
             foreach my $mf2 ( @states )
             {
                 my $lt = $mf2 ? q{processed time} : q{n/a};
             }
         },
      upallnight => sub
         {
             foreach my $mf2 ( @states )
             {
                 my $lt;
                 $lt = q{processed time} if $mf2;
                 $lt = q{n/a} unless $mf2;
             }
         },
   });

[download]

Here's the output

             Rate upallnight    tirwhan
upallnight 22.6/s         --       -22%
tirwhan    29.1/s        29%         --

[download]

(Usually when I post benchmarks someone points out that I've got it completely wrong so I'll probably get shot down in flames for this ;-)

Cheers,

JohnGG

In reply to Re^3: Foreach Loop Optimization by johngg
in thread Foreach Loop Optimization by upallnight

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.