I have discovered some interesting behavior with the exists() command when testing multi-keyed hashes. Given the following hash: 
my %List;
$List{"a"}{"1"} = "yes";
$List{"a"}{"2"} = "no";
$List{"b"}{"1"} = "possibly";
$List{"b"}{"2"} = "never";

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If I use exists() to test for a subkey, it creates a new instance. To demonstrate, use the above hash with this code: 
print "Before:\n";
foreach my $priKey (sort keys %List)
{
    print "$priKey\n";
}
if (exists $List{"c"}{"1"} )
{
    print "found a bad one\n";
}
print "After:\n";
foreach my $priKey (sort keys %List)
{
    print "$priKey\n";
}

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This will give the output: 
Before:
a
b
After:
a
b
c

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Is this correct behavior that I need to code around or is it a bug? It seems to me that exists should never create a key, being a test-only operation, but I wanted to see if the Monks agree. The perl version used for the above is 5.6.1 on Solaris, but it appears to be acting the same way on other versions.

In reply to Unexpected exists() behavior by tsmoyers

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