> The expected result is : 0

... and this ...

> return if not $data;

... collide, because 0 is false in Perl.

You want to try defined or even better just check the size of @arrX °

BTW: This code looks weird, what's your real intention?

HTH! =)

update

°)... e.g. like in return unless @arrX

... which is very Perlish, boolean context is subcase of scalar context which returns the size.

And as we know now that 0 is false ;-)

Hi Lanx,

Thanks for your reply. Regarding my "weird code", the underlying concept is the "Throttle" example from this AnyEvent::HTTP tutorial (http://perlmaven.com/fetching-several-web-pages-in-parallel-using-anyevent).

If you think that way of doing things is weird, do let me know ! I don't want to do weird stuff that might come and bite me in the backside later !

Perhaps to clarify my "real intention" even further than my previous reply, I'm planning to loop through an array of offset counts so that I can use AnyHTTP to upload blocks of a large file to a REST API in parrallel.

Unfortunately I'm not qualified to talk about AnyEvent et. al.

Your code looked strange because of all the closures, but in the case of defining simultaneous call backs this looks like the way to go. :)

Cheers Rolf
_{(addicted to the Perl Programming Language and ☆☆☆☆ :)
Je suis Charlie!}

return if not $data; returns from sub sendX when $data is 0 (a false value).

See also: Truth and Falsehood, and Basic debugging checklist, especially point 2.

ForeverLearning,

Forget about this answer, looked again, and I'm wrong! Not enough coffee yet!

This:

for (1 .. $max) {
   sendX;
}
[download]

for (0 .. $max) {
   sendX;
}
[download]

Regards...Ed

I think the key thing is the use of "if not defined" instead of a numeric/Boolean comparison. A 0 or 1 start for loop doesn't matter (0,1,2,3) or (1,2,3), and actually $count and $max in the sub() don't really either as far as the sub is concerned except that those factors limit the number of times the sub is called in the for() loop. In the OP's code using 1..$max calls the sub 3 times, using 0..$max calls it 4 times.

#!/usr/bin/perl

use 5.014;
use strict;
use warnings;
use autodie;

my @arrX = (0,4194304,8388608);

my $count = 0;  #makes no difference in sub
my $max = 300;  #makes no difference in sub

sub sendX {
        my ($data) = shift @arrX;
        return if not defined $data; # use defined, not numeric/boolea
+n
        say $data;
}


for (1 .. $max) {  #could be 1 .. scalar(@arrX)???
   sendX;
}
__END__
Prints:

0
4194304
8388608
[download]

I am also a bit mystified as to how this relates to some purpose.