Lecture 2 Objectives

At the end of today's class you should

KNOW:

That an interface is the way to represent an itemization (union of classes) in Java
That when an instance of a class invokes a method, the method definition lookup is dispatched to the class to which the instance belongs
That Java programs should not have conditionals on the type of an object (Java's method dispatch obviates the need for a conditional)
That a method specified by an interface must be defined with the same signature in all classes that implement the interface

BE ABLE TO:

Design methods for unions of data in Java

Sample Exam Question:

Add a class Tiger to the IAnimal interface. A Tiger has a name, length, and the number of pounds of meat it consumes daily. Develop a method hasGivenName over IAnimals that consumes a name and produces true if the animal has the given name. The method produces false for animals that don't have a name.