I ultimately want to traverse a hash of unknown topology to determine if I have reached leaf nodes (no hashes exist beneath the current reference). The following test code:

#!/usr/bin/perl

use strict;

my %hash;

print "'hash' is a hash reference\n" if ref(\%hash) eq 'HASH';

$hash{key} = 'value';
print "'hash' is still a hash reference\n" if ref(\%hash) eq 'HASH';
print "'hash{key}' is a scalar reference\n" if ref(\$hash{key}) eq 'SC
+ALAR';
print "'hash{key}' is a hash reference\n" if ref(\%{$hash{key}}) eq 'H
+ASH';
[download]

gives me the error Can't use string ("value") as a HASH ref while "strict refs" in use when I try to test $hash{key} for a type that it isn't on the final line.

How do I go about testing each node in the tree to determine whether I can go further down the structure?

Thanks.

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.