title: Difference between Map.put and Map.putAll methods?
body: <p><code>Map.putAll</code> is equivalent to that of calling <code>Map.put(k, v)</code> on the map once for each mapping from key k to value v in the specified map. So with the functional aspect, both are same.  </p>
  
  <p>So, I am curious to know what are the other differences and when to use which one?</p>