1. Chapter 6 Classes & Objects

2. Learning Java through Alice 2 © Daly and Wrigley Class A class defines a particular kind of object. Each class is a blueprint that tells Alice exactly how to create and display an object. Classes begin with a capital letter.

3. Learning Java through Alice 3 © Daly and Wrigley Objects When an object is created and displayed, we call this instantiating the class because an object is an instance of that class. Object names begin with a lowercase letter.

4. Learning Java through Alice 4 © Daly and Wrigley Object-Oriented Programming Concepts Encapsulation - lets you create a program (class) that describes data and methods that you want to use as a template to create objects. Inheritance - enables you to create a class that is similar to a previously defined class, but one that still has some of its own properties. Polymorphism – allows you to create new objects that perform the same methods as the base object but which perform one or more of these functions in a different way. ▫ Overloading ▫ Overriding

5. Learning Java through Alice 5 © Daly and Wrigley Declaring Objects Cow cow1 = new Cow ( ……..); Adult emily = new Adult ( …..); Button clearButton = new Button ( );

6. Learning Java through Alice 6 © Daly and Wrigley Constructor A constructor is a method with the same name as the class (including case sensitivity). A class can contain several constructors to provide a variety of means for initializing objects of that class. MyFishy nemo = new MyFishy( ); public MyFishy( ) { }

7. Learning Java through Alice 7 © Daly and Wrigley Alice Setters and Getters