1. Repetition in Control flow; Array data structure Chapter 5

2. Key Class Key //class name //Data private boolean isDown; // key status not down or down private String key; //key name private String sound; // key sound //methods //constructor: to initialize the characteristic of the key public Key (String keyName, String soundFile) // create a Key object and initialize // other methods public void act () // mimic the motion of the key going down: animating the key public void play() // play the sound corresponding to the key: producing the sound ….

3. Piano Class Piano //data whiteKeys // keyboard keys corresponding to white keys whiteNotes //wave files for white keys blackKeys blackNotes //methods Default constructor // instantiate Key object for the keys and place them on the Piano public void makeKeys()

4. Classes and Relationships Piano Actor Key IS A Inheritance relationship HAS A Aggregation relationship1 n

5. New Concepts Classes and relationships: is-a and has-a relationships Array data structure to store key information (letter, sound) Loop control structure to repeat operations/instructions

6. 10 things We will do it next class