Re: Is there a True Boolean type in Perl?

On 10/15/07, Michael Barto <mbarto@[EMAIL PROTECTED]
> wrote:
>  As both Java and Javascript both have a 'true' and 'false' or Boolean
data type, is
>  there any interest in evolution of Perl to have a true Boolean. Or what
is the
> preferred method to do this in Perl. The "C" programmers want me to use
"0"'s
> and "1"'s.
snip

Perl 5 does not have a boolean type.  Perl considers the following
things as false: any number that is equivalent to 0 (0.0, 0e0, etc.),
the string '0', the empty string, undef, or an empty list ( i.e. ()).
Anything else is considered true.  Note that the string "0e0" which
evaluates in a numeric context to 0 is not false, but the number 0e0
is false.  In general the values 1 and 0 are used just like they are
in C.

#!/usr/bin/perl

use strict;

my @[EMAIL PROTECTED]
 = (undef, 0, 0.0, 0e0, '', "0e0", "0 but true", 1, "foo");

print "() is ", ( () ? 'true' : 'false' ), "\n";
for my $val (@[EMAIL PROTECTED]
) {
        print "[$val] is ", ($val ? 'true' : 'false'), "\n";
}