Yes, this is how it SHOULD work, but it doesn't! Let me simplify this script a little bit to demonstrate the problem. Run this script below. It should say TEST return value = 77 (at least it does on my computer which is Microsoft Windows 7 running TinyPerl 5.8.) But then you change the "return $N;" to "return $N + 0;" (and remember, at this point, $N is 77, so adding zero to it should leave it the same. But instead of returning 77, it flips its value BACK TO THE ORIGINAL!! which is totally WEIRD behavior! The return value should be 77, not 55. 
#!/usr/bin/perl -w

use strict;
use warnings;

my @TEST_VALUES = ('55a', 'a55');
foreach my $i (@TEST_VALUES)
{
  print "Calling TEST('$i'): ";
  print "\nTEST return value = ", TEST($i), "\n\n\n";
}
exit;

#######################################
sub TEST
{
  my $N = shift;
  local $SIG{__WARN__} = sub { print "\nWarning was triggered. N=$N ";
+ $N = 77; print " Now N is $N  **END OF WARNING**\n"; };
  print "\n N=$N   N+0= ";
  print "ADDITION: ", $N + 0;
  print "\n N=$N ";
  return $N;
}

[download]

I think, I found a BUG in the Perl interpreter. Lol ;)

In reply to Re^2: Converting to number doesn't always work... by harangzsolt33
in thread Converting to number doesn't always work... by harangzsolt33

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