title: JAVA collections, no duplicates
body: <p>I want to discuss a question about java collection framework. Here is the question:</p>
  
  <p>You need to store elements in a collection that guarantees that no duplicates are stored. Which one of the following interfaces provide that capability?</p>
  
  <p>a.java.util.List</p>
  
  <p>b.java.util.Collection</p>
  
  <p>c.java.util.Map</p>
  
  <p>d.none of the above</p>
  
  <p>It is pretty clear that the first two options are incorrect, but which one is true c. or d. and why?
  Personally, my answer is d.none of the above.</p>