Fellow monks...

I'm banging through Perl Objects, References and Modules to get my head around references and complex data structures. At the same time, I'm writing a set of sub-routines to automate a telnet session and parse the resulting text from that session. In trying to integrate what I'm learning in the book to this work, I decided to write some of the subs to return references to hashes or arrays; however, it didn't take me very long to get in trouble. The simple ( and pointless ) code below illustrates the issue: 

#! /usr/bin/perl

use strict;
use warnings;

my $ref = return_ref();
if ( !ref ) {
    print "No hash reference.\n";
}
else {
    print "We have a hash reference.\n";
}

sub return_ref {
    my %hash;
    return \%hash;
}

[download]

To my initial surprise, the code above printed "We have a hash reference.", even though the hash I've referenced is empty ( ie: no keys and no values ).
I've since figured out that I need to de-reference the reference before checking for truthfulness. I'm guessing this is because the code above is checking for truthfulness on the memory address of the empty hash ( which should always be true, ie: > 0 ) and not on the hash itself?

Is this correct? Or am I missing something?
Thanks in advance!
njcodewarrior

In reply to Truthfulness of references by njcodewarrior

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