On 10/15/07, Michael Barto <[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 @a = (undef, 0, 0.0, 0e0, '', "0e0", "0 but true", 1, "foo");
print "() is ", ( () ? 'true' : 'false' ), "\n";
for my $val (@a) {
print "[$val] is ", ($val ? 'true' : 'false'), "\n";
}
