Homework 5
Exercise 15.x1: One can show the subtype relation on Java types by drawing a diagram with arrows, where each arrow points from a subtype to one of its supertypes. Arrows can be omitted that are implied by transitivity. As a simple example, if the types under consideration are
Integer
,Number
, andObject
, one would draw an arrow pointing fromInteger
toNumber
and a second arrow pointing fromNumber
toObject
, but there would be no need to show an arrow fromInteger
directly toObject
. Using this diagramming convention, show the subtyping relation onList<?>
,ArrayList<?>
,List<Number>
,ArrayList<Number>
,List<Integer>
, andArrayList<Integer>
.Do exercise 16.3 on page 315-316. Assume that the interfaces are defined as follows:
interface I1 {}; interface I2 {};