Sum of values in an array

[Anonymous Monk]

Hi Monks!
I would like to have a total sum of the values from this array of hashes, any suggestions?

...
print Dumper \@pe_total;

$VAR1 = [
{
'COMP_TOTAL' => '2445.00'
},
{
'COMP_TOTAL' => '728.00'
}
];
...

Thanks for help!

[toolic]

One way:

use warnings;
use strict;
use List::Util qw(sum);

my @pe_total = (
    {
    'COMP_TOTAL' => '2445.00'
    },
    {
    'COMP_TOTAL' => '728.00'
    }
);

print sum(map { $_->{COMP_TOTAL} } @pe_total), "\n";

__END__

3173

See also:

• perldsc

[Anonymous Monk]

Would it be possible to be done without loading a Perl Module?

[Anonymous Monk]

List::Util is in the Perl core. Try it out, you should already have it installed.

Otherwise, BrowserUk has given you an alternative method.

[toolic]

Would it be possible to be done without loading a Perl Module?

Yes. Yes, it can.

[BrowserUk]

Updated to address GrandFather's concern below.

my @pe_total = (
     {
     'COMP_TOTAL' => '2445.00'
     },
     {
     'COMP_TOTAL' => '728.00'
     }
 );;

my $total;
$total += $_->{COMP_TOTAL} for @pe_total; 
print $total;;
3173

[GrandFather]

I was surprised by my $total += $_->{COMP_TOTAL} for @pe_total; so I ran the code. No output generated so I modified the print to print "$^V >$total<"; which prints:

v5.16.3 ><

What is different about the way you are running the sample code? Different Perl verion maybe?

The B::Deparse of the summing line is:

(my $total += $$_{'COMP_TOTAL'}) foreach (@pe_total);

but my Perl foo isn't strong enough to decide if that means $total is local to the loop body or not. The result implies that it is, at least for this version of Perl.

[BrowserUk]

You're right. I ran it in my REPL, thus globals; and added the my when posting (to encourage its use). Now corrected above. Thanks.