1. 2.1 Introduction to Object-Oriented Programming

2. 2.1.1 Procedural versus OOP languages
Procedural programming involves creating a sequence of instructions
OOP uses a collection of interacting objects
Functions are logically grouped, making enhancements easy
OOP can model human problem-solving

3. 2.1.2 Basic Java terminology
Object. contains data and instructions
Class. blueprint for an object
Attribute. describe the state of objects
Data Type. describes what kind of information a certain attribute is
Behavior. describe what objects can do
Method. a set of instructions
Inheritance. Some objects derive attributes and behaviors from other objects
Encapsulation. Combining data and methods together

4. 2.2 What are Objects? 2.2.1 Introduction to objects
Anything tangible or abstract that is relevent
Objects can have attributes and behaviors
Attributes describe the object
Behaviors describe what the object can do

5. 2.2.2 Classification of objects
User Interface objects
Objects that the user interacts directly with
Operating environment objects
Provide services to other components
Task Related objects
Documents, multimedia, problem domain

6. 2.2.3 Objects - identifying, defining, creating and operating on
Identifying – Requires needs assessment
Defining – Classification, relationships, operations. The class keyword
Creating – The constructor and the new keyword
Operating – Using an object’s methods

7. 2.2.7 Encapsulation To hide the details, package together
Access modifiers – public, private and protected

8. 2.2.8 Object relationships Association Whole-part Inheritance
Objects know about each other
Whole-part
Existance of an object relies on another
Inheritance
Attributes & behaviors can be inherited

9. 2.2.9 Inheritance

10. 2.2.10 Object mutability and destruction
Some object attributes should be immutable, or unchangable
To make an item immutable, use the final keyword
The JVM automatically releases memory when objects are no longer required
The garbage collector will reclaim memory by objects that are no longer referenced
Garage collection is not controllable

11. 2.3.1 Modeling languages and symbols
Unified Modeling Language (UML) standardizes symbols & terminology for diagramming objects

12. 2.3.2 Basic Class symbol Rectangle represents a class of objects
3 compartments: Name, attributes , and operations or methods
Symbols indicate accessibility

13. 2.4.1 Class definition Defined by using the class keyword
Public classes defined in separate files
Filename must be the same as the class name
public class Person {
private String name;
public Person(String theName) {
name = theName; }

14. 2.4.2 Creating objects
Constructor methods are called when an object is created
All object data is stored in memory
Variables are a reference to the memory location

15. 2.4.3 Object methods Mutator – Changes object data
Accessor – Retrieves object data
Methods with no arguments
Methods that require arguments
Method return values – Provide a result to the caller

16. 2.5.1 System class Data stored by an object is member data
Data present in an object’s methods is called local or temporary data
Java.lang.System is a pre-defined object that can be used to perform system tasks
System.out.println(“Hello World!”);