Think of a List class. Let's say it has methods to add, remove and retrieve elements, and it has a method to retrieve the size.
Let's say the internal implementation is an array with a fill pointer.
Obviously, before you can usefully call list.get(7), you must have called list.add(T) at least 7 times (assuming no deletes).
Do you need to know the the state of the backing array and the value of the fill pointer? Do you need to know whether there even is a fill pointer, or a linked list underneath (obviously, the performance would be different so you would need to know at some point)?
Think of a List class. Let's say it has methods to add, remove and retrieve elements, and it has a method to retrieve the size.
Let's say the internal implementation is an array with a fill pointer.
Obviously, before you can usefully call list.get(7), you must have called list.add(T) at least 7 times (assuming no deletes).
Do you need to know the the state of the backing array and the value of the fill pointer? Do you need to know whether there even is a fill pointer, or a linked list underneath (obviously, the performance would be different so you would need to know at some point)?