Question

Hi I have a hash where the key is a 3digit code and value is number of elements under that code. I want to sum the 3digit code and multiply with the number of elements, then finally add them up. Example:

000 23
012 42
222 34

[(0+0+0)*23]+[(0+1+2)*42]+[(2+2+2)*34]=0+126+204=330

so i tried

foreach my $key (sort keys %hash ){      
@arrSum=split(//, $key);
   foreach $i (@arrSum){    
     $sum+=$i;
     $value=$sum*$hash{$key};
   }    
}

It does not work. It actually has to consider each line, instead it sums up all the 3digit code at once. Need some help.

Answer 1

Here is more functional approach to the problem, it also uses sum from List::Util:

use List::Util qw(sum);

my %hash = qw(
    000 23
    012 42
    222 34
);

print sum(map { sum(split //) * $hash{$_} } keys %hash);     # 330