Object Oriented Programming

TeguhSutanto Si | STIKOM Surabaya

teguh@stikom.edu|+628563076813|http://teguhsutanto.blogspot.com|http://blog.stikom.edu/teguh

GOAL

1.Students can understand the Object Oriented Programming concepts

2.Students can make a program in accordance with the rules of Object Oriented Programming

Object-oriented programming (OOP) is a programming paradigm using "objects" – data structures consisting of data fields

and methods together with their interactions –

to design applications and computer programs

Object-oriented programming (OOP) is a programming language model organized around "objects" rather than "actions" and

data rather than logic. Historically, a program has been viewed as a logical

procedure that takes input data, processes it, and produces output data

Why OOP?

1.Object-oriented systems can be easily upgraded from small to large scale.

2. It is easy to partition the work in a project based on objects.

3.Object-oriented programming offers a new and powerful model for writing computer software.

4. It reduces software maintenance and developing costs.

5.Changes in user requirements or later developments have always been a major problem.

6.Object-orientation or object oriented programming (OOP) should help one in developing high quality software easily.

Concept of Class and Object

• “Class” refers to a blueprint. It defines the variables and methods the objects support

• “Object” is an instance of a class. Each object has a class which defines its data and behavior

Concept of Class and Object

Classes reflect concepts, objects reflect instances that embody those

concepts

Daria JaneBrittany

Jodie

girlclassobject

Class:A class can have three kinds of members:

Attribute/Field/Data

Method

Field Declaration

• a type name followed by the field name, and optionally an initialization clause

• primitive data type vs. Object referenceo boolean, char, byte, short, int, long, float,

double• field declarations can be preceded by

different modifierso access control modifierso statico final

Acces Control Modifier

1.private: private members are accessible only in the class itself

2.package: package members are accessible in classes in the same package and the class itself

3.protected: protected members are accessible in classes in the same package, in subclasses of the class, and in the class itself

4.public: public members are accessible anywhere the class is accessible

comPerson

• name: String• address: String

# age: int+getName(): String

Employee HRD

X

MainMenuX

public class Pencil {public String color = “red”;public int length;public float diameter;private float price; public static long nextID = 0; public void setPrice (float newPrice) { price = newPrice; } }

public class CreatePencil {public static void main (String args[]){Pencil p1 = new Pencil();p1.price = 0.5f; }

}

Pencil.java

CreatePencil.java

%> javac Pencil.java%> javac CreatePencil.javaCreatePencil.java:4: price has private access in Pencilp1.price = 0.5f;^