in reply to Re: Hash problem - Perl noob
in thread Hash problem - Perl noob

Why
for (my $i=0;$i<=$#phrase;$i++)
over the equally efficient yet much more readable
for my $i (0 .. $#phrase)

Replies are listed 'Best First'.
Re^3: Hash problem - Perl noob
by tinita (Parson) on Sep 16, 2006 at 09:07 UTC
    over the equally efficient ...
    i think a "foreach loop" is more efficient, but maybe i'm making a mistake in my benchmark? 
    perl -wle'
use Benchmark;
my $max = $ARGV[0];
timethese($ARGV[1]||-1, {
  for     => sub { for (my $i=0;$i<$max;$i++) { 1 } },
  foreach => sub { for my $i (0..$max-1)      { 1 } },
}
)' 10000 2000

Benchmark: 
timing 2000 iterations of
 for, foreach
...

       for:  8 wallclock secs ( 7.63 usr +  0.00 sys =  7.63 CPU) @ 26
+2.12/s (n=2000)

   foreach:  5 wallclock secs ( 5.38 usr +  0.00 sys =  5.38 CPU) @ 37
+1.75/s (n=2000)

    [download]
[reply]
[d/l]
      I thought it might be. You test looks fine, and I'm getting similar results. 
               Rate     for foreach
for     531/s      --    -38%
foreach 854/s     61%      --

      [download]
[reply]
[d/l]
Re^3: Hash problem - Perl noob
by ptum (Priest) on Sep 15, 2006 at 17:25 UTC

    No good reason ... personal style (or lack thereof), "that's the way I originally learned it", etc. Thanks for reminding me (and the OP) of a better alternative. :)

[reply]

In Section Seekers of Perl Wisdom