Concatenating strings from a multidimensional array overwrites the target string in Perl

Question

I've built a two dimension array with string values. There are always 12 columns but the number of rows vary. Now I'd like to build a string of each row but when I run the following code:

$outstring = "";
for ($i=0; $i < $ctrLASTROW + 1; $i++) {
    for ($k=0; $k < 12; $k++){
       $datastring = $DATATABLE[$i][$k]);
       $outstring .= $datastring;
    }
}

$outstring takes the first value. Then on the second inner loop and subsequent loops the value in $outstring gets overlaid. For example the first value is "DATE" then the next time when the value "ABC" gets fed to it. Rather than being the hoped for "DATEABC" it's "ABCE". The "E" is the fourth character of DATE. I figure I'm missing the scalar / list issue but I've tried who knows how many variations to no avail. When I first started I tried the concatenation directly from the @DATATABLE. Same problem. Only quicker.

Answer 1

When you have a problem such as two strings DATE and ABC being concatenated, and the end result is ABCE, or one of the strings overwriting the other, a likely scenario is that you have a file from another OS, with the line endings \r\n, which are chomped, resulting in the string DATE\rABC when concatenated, which then becomes ABCE when printed.

In other words:

my $foo = "DATE\r\n";
my $bar = "ABC\r\n";   #  \r\n line endings from file
chomp($foo, $bar);     #  removes \n but leaves \r
print $foo . $bar;     #  prints ABCE

To confirm, use

use Data::Dumper;
$Data::Dumper::Useqq = 1;
print Dumper $DATATABLE[$i][$k];   # prints $VAR1 = "DATE\rABC\r";

To resolve, instead of chomp use a regex such as:

$foo =~ s/[\r\n]+\z//;