java arraylist ensureCapacity not working

Question

Either I\'m doing this wrong or i\'m not understanding how this method works.

ArrayList a = new ArrayList();
a.ensureCapacity(200         


        

Answer 1

Once again JavaDoc to clarify the situation:

Throws: IndexOutOfBoundsException 
    - if index is out of range (index < 0 || index > size()).

Note that size() returns the number of elements currently held by the List.