just for completeness: you can also say...

@myArray = ('common Value1',
            'common Value2',
)
     unless scalar @myArray;
[download]

NOTE: This type of solution breaks down if the user sets @myArray (or %myHash) to an empty array in their conf file (but your existing system of setting scalars breaks down the same way if they have $foo = 0; in their conf file)