"$Bill Luebkert"
<[EMAIL PROTECTED]> To: Philip Morley
<[EMAIL PROTECTED]>
cc:
[EMAIL PROTECTED]
05/11/02 12:31 Subject: Re: Evaluating
multi-dimensional hashes
Philip Morley wrote:
> $VAR1 = {
> 'level1' => {
> 'level2' => {
> 'level3' => {}
> }
> }
> }
>
>
> The above is the contents of a multi-dimensional hash I have produced
from
> parsing an XML String. (The Data::Dumper formatting has been adjusted
for
> brevity).
>
> What I want to do is check whether level3 is "null" (i.e. contains no
value
> or sub-hashes), but I can't work out a way of expressing this.
>
> I have the reference to the hash, named $XMLRef, and when printing
> something like:
>
> print "$$XMLRef{level1}{level2}{level3}";
>
> I get a HASHREF printed.
>
> How can I evaluate if $$XMLRef{level1}{level2}{level3} is null?
Maybe something like this:
my %hash = (
'level1' => {
'level2' => {
'level3' => { }
}
}
);
my $XMLRef = \%hash;
print scalar keys %{$XMLRef->{level1}{level2}{level3}}, "\n";
__END__
Thanks fo that.
One extra question -
print scalar keys %{$XMLRef->{level1}{level2}{level4}}, "\n";
will print 0 with the above example. How can I tell if a subkey exists in
a hash (level4 doesn't in this example)?
Thanks,
Phil.
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