#!/usr/bin/perl -w

use strict;
use warnings;

my %foo;

if(exists($foo{qux})) {
	print "\$foo{qux} exists";
}

if(exists($foo{bar}{baz})) {
	print "\$foo{bar}{baz} exists\n";
}

if(exists($foo{bar})) {
	print "\$foo{bar} popped into existence\n";
}

if(exists($foo{qux})) {
	print "\$foo{qux} popped into existence\n";
}