adding all elements of an array

[carpeliam]

I can't remember if there's a shortcut for adding all elements of an array in Perl.. it sounds like the kind of thing that Perl would be able to do, so I thought I'd ask. The quickest way I know is something like this:

my $total_size = 0;
foreach $item (@array) {
$total_size += $item;
}

Is there a quicker way? Thanks.. Liam Morley
lmorley@wpi.edu
"light the deep, and bring silence to the world.
light the world, and bring depth to the silence."

 

[sackyhack]

You could use map or grep, but I'm not sure that would be any faster:

my $total_size = 0;
map {$total_size += $_} @array;

or

my $total_size = 0;
grep {$total_size += $_} @array;

 

[sophisticate]

You could also use an eval and join.. Like sackyhack, I'm not sure if this is any faster.

eval join '+',@array;

brendanc@icehouse.net

 

[tsdragon]

I would never have thought of using eval and join! Clever solution, whether it's faster or not.
Tracy Dryden
tracy@bydisn.com

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard.

 

[sophisticate]

For the fun of it, I ran all of these methods through the Benchmark module. It appears that, while it may be a lot smaller, eval is actually the slowest route (by a significant margin). And even though it's usually considered bad form to use it in a void context, grepping was consistently the fastest. Who would've thought?

brendanc@icehouse.net

 

[tsdragon]

I would have guessed that eval would be the slowest, because of what's involved. I MIGHT have guessed that grep or map would be faster than the for loop, since it would (presumably) be optimized internally. It's nice to know for sure.

Tracy Dryden
tracy@bydisn.com

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard.