Summary Java is a widely used object-oriented programming language and software platform that runs on billions of devices, including notebook computers, mobile devices, gaming consoles, medical devices and many others. The rules and syntax of Java are based on th

Chapter 5
Programming with Objects and Classes
) OO Programming Concepts
) Declaring and Creating Objects
) Constructors
) Modifiers (public, private and static)
) Instance and Class Variables and Methods
) Scope of Variables
) Use the this Keyword
) Analyze Relationships among Classes
) Case Studies (Mortgage class and Rational class)
) The Java API and Core Java classes
) Processing Strings (String, StringBuffer, and
StringTokenizer)

, OO Programming Concepts
• Classes are blueprints or structures for defining objects
• Each object is an instance of class
• In Java, each object has data which are used to describe
properties, and methods which are used to describe behaviors
• Each Java file is a class


Class object

, OO Programming Concepts

Class construction Data member1
Data member2
properties
…
Data memberN



Method1
behaviors
Method2
…
MethodM

, Class and Objects
Circle class
Circle Graphical
notation for
radius classes

findArea

new Circle() new Circle()

circle1: Circle circlen: Circle Graphical
notation for
radius = 2 ... radius = 5 objects