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

 my $heap = {};

 $heap->{'172.16'} = 1;
 print "\$heap->{'172.16'}: $heap->{'172.16'}\n";
 print "\$heap->{172.16}: $heap->{172.16}\n";

 $heap->{'127.2'}{'127.1.0.2'} = 2;
 print "\$heap->{'127.2'}{'127.1.0.2'}: $heap->{'127.2'}{'127.1.0.2'}\n";
 print "\$heap->{127.2}{127.1.0.2}: $heap->{127.2}{127.1.0.2}\n";

##</code><code>##

$heap->{'172.16'}: 1
$heap->{172.16}: 1
$heap->{'127.2'}{'127.1.0.2'}: 2
Use of uninitialized value in concatenation (.) or string at /home/larry/project/sysmonitor/test/testHash2.pl line 28.
$heap->{127.2}{127.1.0.2}: