Chapter 7 Classes & Objects

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.

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.

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

Declaring Objects Cow cow1 = new Cow ( ……..); Adult emily = new Adult ( …..); Button clearButton = new Button ( );

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( ) { }

Alice Setters and Getters