MODUL 1

CLASS

A.    Objective

To Understand what is class and make student can create class it self.

B.     Basic Teory

Class is blueprint from object. Some object can created from project that called class. Basic on this definition, then a sufficient class made just one part of the class and can be created / unloaded several objects (tens or even hundreds) that have the same properties

C.     Tools and Materials

·         Laptop

·         Software NetBeans

·         Java Development Kit (JDK)

D.    Work Step

This is some implementation of bicycle class :

public class bicycle {

    int candance;

    int speed;

    int gear;

   

    void changeCandance (int newValue){

        candance = newValue;

   

    }

    void changeGear (int newValue){

        gear = newValue;

    }

    void speedUp (int increment){

        speed = speed + increment;

    }

    void applyBreak (int decrement){

        speed = speed - decrement;

    }

    void printStates(){

        System.out.println("Speed = "+speed+", "+"Gear = "+gear+", "+"Candance = "+candance);

    }

}

Class Bicycle above do not have a main function (main method) because this class is not an application program but merely a blueprint to create. To run an application program, it must be given a class that has a primary function.

public class BicycleDemo {

    public static void main(String []args){

        bicycle bike1 = new bicycle();

        bicycle bike2 = new bicycle();

       

        bike1.changeCandance(50);

        bike1.speedUp(10);

        bike1.changeGear(2);

        bike1.printStates();

       

        bike2.changeCandance(50);

        bike2.speedUp(10);

        bike2.changeGear(2);

        bike2.changeCandance(40);

        bike2.speedUp(10);

        bike2.changeGear(3);

        bike2.printStates();

    }

}

Execute :

run:

Speed = 10, Gear = 2, Candance = 50

Speed = 20, Gear = 3, Candance = 40

BUILD SUCCESSFUL (total time: 2 seconds)

E.     Analysis

To make class we must have blueprint and main method to run some java program.

Ern4t

F.      Assignment

1.      Create a class that can present the properties of the object cat. This object has the form {umur, warna bulu} and function of the form {meow, ulang tahun}.

Code :

public class cat {

    String warnabulu;

    int umur;

   

    void changeWarnabulu (String colour){

        warnabulu = colour;

    }

           

    void changeUmur (int newValue){

        umur = newValue;

    }

    void printState(){

        System.out.println("WarnaBulu = "+warnabulu+", "+"meong, "+"Ulang tahun ke = "+umur);

    }

}

public class catDemo {

    public static void main(String []args){

        cat cat1 = new cat();

        cat cat2 = new cat();

       

        cat1.changeWarnabulu("White");

        cat1.changeUmur(2);

        cat1.printState();

       

        cat2.changeWarnabulu("Black");

        cat2.changeUmur(1);

        cat2.printState();

    }

}

Execute :

run:

WarnaBulu = White, meong, Ulang tahun ke = 2

WarnaBulu = Black, meong, Ulang tahun ke = 1

BUILD SUCCESSFUL (total time: 2 seconds)

2.      One of the application PBO is a very common form of financial applications. Bank Account is one of the things that can be used as an object in the PBO.

                                                              i.      Create a class that can present the account object. variables of this object is {saldo, no rek, nama} and function of the form {cek saldo, menabung, menarik, and transfer}.

                                                            ii.      Create a class that has a main function that is used to demonstrate the making of the object.

Code :

public class ObjectRekening {

    int saldo;

    int noRek;

    int sisa;

    int transfer;

    int menabung;

    int checksaldo;

    String nama;

   

    void changesaldo (int newValue){

        saldo = newValue;

        System.out.println("Saldo Anda = "+saldo);

    }

    void changenorek (int newValue){

        noRek = newValue;

        System.out.println("Nomer Rekening Anda = "+noRek);

    }

    void changenama (String name){

        nama = name;

        System.out.println("Nama Anda = "+nama);

    }

    void changetransfer (int newValue){

        transfer = saldo - newValue;

        checksaldo = transfer;

        System.out.println("Dana yang Di Transfer = "+newValue);

    }

    void changemenabung (int newValue){

        menabung = saldo + newValue;

        checksaldo = menabung;

        System.out.println("Anda Menabung = "+newValue);

    }

    void checksaldo (){

        saldo = checksaldo;

        System.out.println("Saldo Anda = "+saldo);

    }

   

}

public class ObjectRekeningDemo {

    public static void main(String []args){

        ObjectRekening Rekening1 = new ObjectRekening();

       

        Rekening1.changenama("Fauzan");

        Rekening1.changesaldo(10000);

        Rekening1.changenorek(123456789);

        Rekening1.changemenabung(25000);

        Rekening1.checksaldo();

        Rekening1.changetransfer(15000);

        Rekening1.checksaldo();

        Rekening1.changemenabung(5000);

        Rekening1.checksaldo();

        Rekening1.changetransfer(2000);

        Rekening1.checksaldo();

    }

}

Execute :

run:

Nama Anda = Fauzan

Saldo Anda = 10000

Nomer Rekening Anda = 123456789

Anda Menabung = 25000

Saldo Anda = 35000

Dana yang Di Transfer = 15000

Saldo Anda = 20000

Anda Menabung = 5000

Saldo Anda = 25000

Dana yang Di Transfer = 2000

Saldo Anda = 23000

BUILD SUCCESSFUL (total time: 0 seconds)

3.      Note the string class is in the java library. specify a list of variables and functions held by the string class.

Homework :

1.      Create a class Kalimat is an application program to count the number of letters of a sentence and also can convert the sentence into a sentence with a capital letter.

Code :

public class Kalimat {

    String w;

   void changeword (String newword){

       w = newword;

       System.out.println("Your words = "+w);

   }

   void counting (){

       System.out.println("The Amount Character = "+w.length());

   }

   void enlarge (){

       System.out.println(w.toUpperCase());

   }

}

public class DemoKalimat {

    public static void main(String []args){

        Kalimat kalimat1 = new Kalimat();

       

        kalimat1.changeword("Teknik Informatika UMS");

        kalimat1.counting();

        kalimat1.enlarge();

    }

}

Execute :

run:

Your words = Teknik Informatika UMS

The Amount Character = 22

TEKNIK INFORMATIKA UMS

BUILD SUCCESSFUL (total time: 0 seconds)