There is nothing wrong with your code. All you really have to add total_revenue processing is to declare $total_revenue outside the loop and add to it inside the loop. However, you can simplify the logic by using stevieb's hash suggestion. 
>type htmanning2.pl
use strict;
use warnings;

my @hash_rows = (
    {total => 3, other_col => 'fie'},
    {total => 6, other_col => 'fum'},
    {total => 5, other_col => 'oop'},
);

my %revenues = (
     3 => 30,
     6 => 48,
    10 => 50,
);

my $total_revenue;
foreach my $pointer (@hash_rows) {  # simulate fetchrow_hashref for po
+st
    my $total = $pointer->{total};
    next if (!defined $total or !exists $revenues{$total});
    my $revenue = $revenues{$total};
    $total_revenue += $revenue;
    print "revenue: $revenue\ntotal_revenue $total_revenue\n\n";
}

>perl htmanning2.pl
revenue: 30
total_revenue 30

revenue: 48
total_revenue 78


>

[download]
Bill

In reply to Re: Adding numbers from a loop by BillKSmith
in thread Adding numbers from a loop by htmanning

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