an int list is not the same type of object as an array, and is not initialized in the same manner. It more closely resembles the ArrayList format, and is initialised in the same manner. Values are added using append and other often used functions have been added for speed and elegance of code.
initialise
ArrayList <type> n = new ArrayList<typr>();
IntList inventory = new IntList();
n.add(value);
inventory.append();
as you can see they closely resemble one another however in the case of the intList the type is already known.