CS51 - Fall 2009 - Lecture 12

looking ahead at schedule for next few weeks.

midterm is 2 weeks from today.

sample midterm: Spring 2006

review of while loops and classes

extended discussion of growing/shrinking ball example (10.5.2)

Interfaces

public methods are what you need to use a class, private methods are for the person implementing the class.

Java interfaces let you note that two different classes are similar in that they each implement a certain set of methods (though they may do so in completely different ways, and each may have additional methods)

ShirtsAndPants

Uses an interface called Laundry, in the Laundry.java file:

            public Interface Laundry {

                public boolean contains(Location pt);
                public void setColor(Color c);

                // also move and moveTo 

            }

Note that there's no constructor

There's no body to any of the methods

Now TShirt and Pants must note that they implement the interface:

            public Class TShirt implements Laundry {

                ...

            }

means that they each contain the methods defined in the Laundry interface

Note how item is declared and used in the main LaundrySorter class.

private Laundry item;

Now can call methods on item that are declared in the Laundry interface.