Question

If I open a file with strings like “233445”, how can I then split that string into digits “2 3 3 4 4 5” and add each one to each other “2 + 3 + 3 etc…” and print out the result.

My code so far looks like this:

use strict;

#open (FILE, '<', shift);
#my @strings = <FILE>;
@strings = qw(12243434, 345, 676744); ## or a contents of a file
foreach my $numbers (@strings) {
   my @done = split(undef, $numbers);
   print "@done\n";
}

But I don’t know where to start for the actual add function.

Answer 1

use strict;
use warnings;

my @strings = qw( 12243434 345 676744 );
for my $string (@strings) {
   my $sum;
   $sum += $_ for split(//, $string);
   print "$sum\n";
}

or

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

my @strings = qw( 12243434 345 676744 );
for my $string (@strings) {
   my $sum = sum split(//, $string);
   print "$sum\n";
}

PS — Always use use strict; use warnings;. It would have detected your misuse of commas in qw, and it would have dected your misuse of undef for split‘s first argument.