The code you have works properly on undef values: 
#!/usr/bin/perl

use vars qw(@day);

$day[5] = '';
printday();
$day[5]="\n";
printday();
$day[5]=undef;
printday();

sub printday
{
  my $len = length($day[5]);
  if ($len =~ /8/) {
    print "$day[5]";
  } else {
    print "00:00:00";
  }
  print "\n";
}

[download]
outputs: 
00:00:00
00:00:00
00:00:00
as expected. So there error is likely to be elsewhere in your code.

Using $len =~ /8/ to see if the length is 8 is very strange. It says "if the string representation of the length contains the digit 8", so will match 8, 18, 3008, 8000000, etc. You probably just want $len == 8.

In reply to Re: Null in Array by sgifford
in thread Null in Array by Pyramid

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