This is why I use !1 as my "false" value. (And I use 0+ to force numeric context.)

The 0+ works but causes a warning. I went with $v||0 as the simplest in this case. I think I said something like $s=join ',', map { $_||0 } @version;.

Just to make sure you didn't miss the point. If you use $f= !1 then 0+$f does not cause a warning. So, if you want $f to stay the empty string, you can also use:     $f ||= !1; if you don't have control over how $f is initially set. Then 0+ and sprintf "%d", etc. will all work without giving a warning.

        - tye

Quoting from perlop:

Unary "+" has no effect whatsoever, even on strings. It is useful syntactically for separating a function name from a parenthesized expression that would otherwise be interpreted as the complete list of function arguments.

Fun Fun Fun in the Fluffy Chair

If you want it to be zero why not just make it so. If will still eval as false in conditionals...

use warnings;
my $v = '';
$v ||= 0;
print "\$v = '$v'";
[download]

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

Re: If you want it to be zero why not just make it so.

This is a version tuple for a C++ DLLs and EXEs. In one place, it is omitted if the "patch" value is not used, and that is the way it appears in the GUI. In another place, I need all 4 numbers separated with commas, regardless.

This is a program that takes release information via a nice user-friendly form, and updates the directory tree, changing all the places the version appears in files. If the program wasn't already using an empty string here (other code formats it different ways in different uses), I'd probably just use numbers consistantly.

So the short answer: maintainance often contradicts good design.

—John