Re^3: Data::Table - empty values - avoid warnings

[GertMT]

okay thanks a lot. I'm almost there but found out that actually the columns I'm working on have a lot of numbers that have as a decimal separator a 'comma'. For example in the blank spot number like 2,3 as opposed to the 'space'. To work around that I thought to do

sub to_int_or_zero {
  my $value = shift;
$value =~ s/,/\./;
  if (defined($value) &&
      $value =~ m/^\d+$/) {
    return $value;
  } else {
    return 0;
  }
}

but it doesn't work. The 2,3 nicely changes into 2.3 but I'm obviously making a very elementary mistake that I can't understand myself at this moment as the row adds up to ... 3
: (

[eric256]

If you check How do I determine whether a scalar is a number/whole/integer/float? you'll see that there are several different regex to choose from depending on what types of numbers you want to allow.

[GertMT]

uhm, well. The numbers with comma's as delimiters are just there and just can't seem to get to 5.3 as the result of the calculation. Well, we'll just go on and a hint is appreciated.
Looked at the regex and now asking myself how to implement that.

[GertMT]

okay I'm there for the moment. Thank you all.
I finally put the regex, I was adviced to use, in the place where it works. Code below could be improved because when starting the first column with a 'space' or nothing there won't show up a 0 (zero) in the column but that also wasn't really where I was after.
Thangs again, rethinking the issue made me learn and get to a solution.

#!/usr/bin/perl
use strict;
use warnings;
use Data::Table;

my $t =
  new Data::Table( [ [ "1", "2", "3" ], [ "10", "20", "2,3" ] ], [ "A"
+, "B" ],
    1 );

# create emtpy column
my @newCol = ();
$newCol[ $t->nofRow - 1 ] = undef;
$t->addCol( \@newCol, 'adding_up' );

# to change , into . in respective columns
# not needed for a correct calculation of col3 though
$t->colsMap( sub { $_->[0] =~ s/,/\./g } );
$t->colsMap( sub { $_->[1] =~ s/,/\./g } );

# Return input if input is an integer, otherwise zero
sub to_int_or_zero {
    my $value = shift;
    if (
        defined($value)

        # the regex that above hints pointed at.
        && $value =~ /^-?\d+\.?\d*$/
      )
    {
        return $value;
    }
    else {
        return 0;
    }
}

# Put the formula in the empty column
$t->colsMap(
    sub {
        $_->[2] = to_int_or_zero( $_->[0] ) + to_int_or_zero( $_->[1] 
+);
    }
);
print $t->csv;