Archive for April 2015
Students are understand about inheritance in java
B. Basic Teory
Inheritance is one of the
main characters from object-oriented programming and very abridging for the
programmers to make and arrange the program. a class tha is inherited from the
parent class will heir all variables and functions from the parent class. in
java, inheritance implementation uses keywords "extends".
C. Tools
and Materials
· Laptop
· Practice Object Oriented Programming
Modul
· Software NetBeans IDE 8.0.2
· Java Development Kit (JDK) 1.8.0_31
D. Work
Step
EXPERIMENT 1
|
Steps
of experiment:
1.
Change Method Aksesor in class
“Bicycle.java” become protected
2.
Write the code program
/**
*
* @author
Octopus_girl
*/
public class MountainBike extends Bicycle {
static
boolean compas = true;
public
static void main (String[]args){
MountainBike mountBike = new MountainBike();
mountBike.speedUp(100);
mountBike.changeGear(6);
mountBike.changeCadence(9);
mountBike.printStates();
mountBike.lookCompas();
}
void
lookCompas(){
System.out.println("ada kompasnya ??"+compas);
}
}
3.
Save file like the name of class
4.
Run and observe the result
EXECISE
|
1.
Make RoadBicycle.java that have special
variable it is diskBreak.
Static int diskBreak =
2;
/**
*
* @author
Octopus_girl
*/
public class RoadBicycle extends Bicycle {
static int
diskBreak = 2;
public
static void main (String[]args){
RoadBicycle roadbicycle = new RoadBicycle();
roadbicycle.speedUp(100);
roadbicycle.changeGear(6);
roadbicycle.changeCadence(9);
roadbicycle.printStates();
roadbicycle.lookdiskBreak();
}
void
lookdiskBreak(){
System.out.println("diskBreak = "+diskBreak);
}
}
2.
Make TandemBike.java class that is have
special variable it is sadel.
Static int sadel = 2;
/**
*
* @author
Octopus_girl
*/
public class TandemBike extends Bicycle {
static int
sadel = 2;
public
static void main (String[]args){
TandemBike tandembike = new TandemBike();
tandembike.speedUp(100);
tandembike.changeGear(6);
tandembike.changeCadence(9);
tandembike.printStates();
tandembike.looksadel();
}
void
looksadel(){
System.out.println("Sadel = " +sadel);
}
}
3.
Run and observe the result
EXPERIMENT 2 (Calling
Constructor super class)
|
In this experiment we will try to access
constructor in super class for subclass.
Steps
of experiment:
1.
Create class “Orang.java”, write the program code:
/**
*
* @author Octopus_girl
*/
public class Orang {
private String nama;
private int usia;
public Orang(String nama, int
usia){
this.nama = nama;
this.usia = usia;
}
//method
public void info(){
System.out.println("Nama : "+nama);
System.out.println("Usia : "+usia+"th");
}
}
2. Create new class with name “Pegawai.java” that is
subclass from ‘Orang.java’ write code program:
/**
*
* @author Octopus_girl
*/
public class Pegawai extends Orang {
protected String noPegawai;
public Pegawai(String
noPegawai, String nama, int usia){
super(nama,usia);
this.noPegawai =
noPegawai;
}
//method
public void info(){
System.out.println("No.Pegawai : "+this.noPegawai);
super.info();
}
}
3.
Create new class with main function ( ),
like picture
/**
*
* @author
Octopus_girl
*/
public class AksesKonstSuperClass {
public
static void main (String[]args){
Pegawai
karyawan = new Pegawai("1245","Mr.Budi",24);
karyawan.info();
}
}
4.
Save file by class name, run and observe
the result
EXERCISE
|
1. Create class “mahasiswaTI.java” that is class
derivative from orang class by show nama, nim, usia and konsentrasi jurusan
/**
*
*
@author Octopus_girl
*/
public class mahasiswaTI extends Orang{
protected String NIM;
protected String Konsentrasi;
public mahasiswaTI(String NIM,String Konsentrasi, String nama, int
usia){
super(nama,usia);
this.NIM = NIM;
this.Konsentrasi = Konsentrasi;
}
//method
public void info(){
System.out.println("NIM Mahasiswa : "+this.NIM);
System.out.println("Konsentrasi Jurusan : "+this.Konsentrasi);
super.info();
}
}
2. Then make class AksesMahasiswaTI.java that have main
function ( ), as implement of class MahasiswaTI.java
/**
*
*
@author Octopus_girl
*/
public class AksesMahasiswaTI {
public static void main (String[]args){
mahasiswaTI mahasiswaTI = new mahasiswaTI("L200134004","Rekayasa
Perangkat Lunak","Anggi",19);
mahasiswaTI.info();
}
}
3. The result
4. Analyst the result
E. Analysis
After running the program, the subclasses are able to access some
variables in the parent class. Not only the variables, but also the
methods, or even the whole characters in parent class. It's means that the inheritance make more simple and help us.
F. Assignment
1.
Is every class must have minimal one constructor? Proved your answer by
try the class is haven’t constructor and try to run it. Attach the class
/**
*
* @author Octopus_girl
*/
public class HitungKarakter {
String x;
void changeword (String
newword){
x = newword;
System.out.println("Silahkan tuliskan kalimat: \n"+x);
}
void counting (){
System.out.println("Jumlah karakternya = "+x.length());
}
void enlarge (){
System.out.println(x.toUpperCase());
}
public static void
main(String []args){
HitungKarakter
kalimat1 = new HitungKarakter();
kalimat1.changeword("Namaku Rahmatul Mahdalina");
kalimat1.counting();
kalimat1.enlarge();
}
}
No, not all class must have constructor. The constructor is just special method that make our work more simple
2.
Observed code and compile the class then watch the error messages and
report.
Edit the class until the error message lost.
Report the result
/**
*
* @author Octopus_girl
*/
public class KucingRumahan extends Kucing {
int kumis; //panjang
kumis, berkurang setiap kali dirawat
KucingRumahan(int kumis){
this.kumis = kumis;
}
KucingRumahan (int kumis,
int umur, String warnabulu){
super();
this.kumis = kumis;
this.umur = umur;
this.warnabulu =
warnabulu;
}
void rawatKumis(){
kumis++;
}
public static void main
(String[]args){
KucingRumahan Kucing
= new KucingRumahan (3,5,"Abu-abu");
Kucing.printStates();
}
}
