title: Can I use dictionaries instead of arrays even if I don't have definitions for keys?
body: <p>Recently I have been using the dictionary object to make arrays with unique values only by taking advantage of the <code>.exists</code> method which is simpler than writing a loop through the entire array every time to see if a value exists.  Then I get the final array by using the <code>.keys</code> method.</p>
  
  <p>Given that the dictionary object requires a definition for each key, I have gone back and forth on what to set as the definition.  Originally I was setting each key's definition to the <code>vbempty</code> constant since I have no use for it anyways.  But would the best practice here be to use a <code>Null</code> value because it would take up less memory?</p>