title: How to get key and value of a TreeMap at particular index
body: <p>I have a TreeMap with a set of 'Key and Value' pairs. How can I get both Key and Value at a particular Index of the TreeMap?</p>
  
  <p>EDIT : @TO-ALL : Thanks. But I know how to implement it by using an extra ArrayList. I just thought is there any way to achieve this without using an extra ArrayList.</p>