On Mon, Jul 09, 2001 at 02:39:15PM -0500, Jay Strauss wrote:
> I'm trying to check if a hash key exists and if the value is 1. I'm passing
> the reference to the hash to a subroutine like:
>
> my $help = 1;
> my %hash = (help=>\$help);
> somefunc(\%hash);
>
> sub somefunc {
> my ($refHash) = @_;
>
> if ((defined $refHash->{help}&& ${$refHash->{help}}) {
> # stuff
> }
> else {
> # other stuff
> }
> }
>
> This seems long an clumsy, I suspect there is a cleaner way to do it in perl
> but I don't know how. I played around with "exists" but that just tells me
> that the value exists. I need to do some processing if the value is "1" and
> other processing for "0";
This is pretty much how you have to do it, I'm afraid.
If you were using 'use strict', however, the 'help' bareword would not
be accepted. I probably would swap 'exists' for 'defined', unless you
might actually set $refHash->{'help'} to undef explicitly, and want to
test for that (but that's just me); also, the ${$refHash->{help}}
could be shortened to $refHash->{'help'}.
So, if you care, here's my version - but it doesn't solve the
"problem" which caused you to ask in the first place :(
sub somefunc {
my $refHash = shift;
if (exists $refHash->{'help'} && $refHash->{'help'}) {
# stuff
} else {
# other stuff
}
}
The difference is pretty much all style, so feel free to ignore it
(except, I really do recommend you use 'use strict').
Micah
