Ok, so you want to see if the hash in that value is empty... I think I get you now ;) Try this:

if (%{$hh{'QUESTION_TEXT'}}){
    # do stuff...
}
else {
    # it's empty, so do different stuff...
}
[download]

It dereferences the inner hashref, and checks if it isn't null (empty).

-stevieb

In addition to stevieb's correct answer, I'll add: there's no such thing as "NULL" in Perl, so that may cause some confusion. Values in Perl may be defined or undefined, as well as true or false. But references (pointers to other things) are always defined and true, even if the thing they point to is empty, as in the case of a hash with no keys and values.

#!/usr/bin/env perl
use 5.010; use warnings; use strict;

my %hash = ();    # create empty hash
my $ref = \%hash; # create reference pointing to empty hash

if($ref){
    say 'Reference is true';   # <- always true
} else {
    say 'Reference is false';
}

if (%$ref){ # derefence hash and check the number of elements in it
    say 'Hash has elements';
} else {
    say 'Hash is empty';    # <-- hash has no elements
}

$hash{a} = 1;  # add a key and value to hash

if (%$ref){ # derefence hash and check the number of elements in it
    say 'Hash has elements';    # <-- now it has one key and one value
} else {
    say 'Hash is empty';
}
[download]

Aaron B.
Available for small or large Perl jobs and *nix system administration; see my home node.

As I said, Stevie's response did not work under "use strict". What finally worked is checking for the literal value of the string "HASH", which is what was printing out for me.

if (!($hh{'QUESTION_TEXT'} =~ /HASH\(/)) {

Now, I thought it printed out this value when you tried to print a hash reference that wasn't defined. I don't understand this, since the Dumper call shows the structure to be like the below:

{
'QUESTION_TEXT' => {},
'VARNAME' => 'OTHER STUFF',
},

So why does my code need to check for literally "HASH(" in the string, when the structure clearly has nothing in it?

This did not work. This complains under "use strict" rules:

Can't use string ("Some actual text here"...) as a HASH ref while "strict refs" in use ...

When I ran without "use strict", it ALWAYS executed the else clause.