Question

So I want to insert a value in a specific index, that mean I would throw exception if the index I want to insert is not exist or bigger than size, otherwise, I would use this method to ensure the capacity of the array is not null:

private void ensureCapacity(int size_wanted)
{
  int max_capacity = storage.length;
  if (size_wanted > max_capacity) 
  {
    max_capacity = max_capacity * GROW_FACTOR +1; 
    storage = Arrays.copyOf(storage, max_capacity); // increases array size + copy contents
  } 
}

Then at this point, I suppose to extend the array and already made a copy of my original with the increased size already, right?

All I need to do is using a loop and shift everything to the right by one, to leave space for the index I want to insert at, correct?

Answer 1

You can use System.arrayCopy to move array like that.
but why are you rebuilding existing functionality provided by ArrayList