Watcharin Puangplia 29/04/2011
Class
attribute
method
Class 2 - attributes ! - methods "# $% $ &
Class
Object A
Object B
Object C
Object D
attribute
method
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length width setLength
Class name Attribute
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Method
Rectangle length wigth setLength() setWidth() getLength() getWidth() getArea()
Object
Class Rectangle
myRec 10
length
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width
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setWidth getLength
getArea
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yourRec 20 15 setLength setWidth getLength getWidth getArea
Music player state: current song volume battery life behavior: power on/off change station/song change volume choose random song
creates Music player #1
Music player #2
Music player #3
state: song = "Thriller" volume = 17 battery life = 2.5 hrs
state: song = "Lovesong" volume = 9 battery life = 3.41 hrs
state: song = "Closer" volume = 24 battery life = 1.8 hrs
behavior: power on/off change station/song change volume choose random song
behavior: power on/off change station/song change volume choose random song
behavior: power on/off change station/song change volume choose random song
[AccessSpecifier] class Attribute Member Method Meber }
Name{
AccessSpecifier , ( (- public class ( ) % 0( 0 ,- 1 Name - $% 1 * Member - 2 , (- Atribute ' Method
[AccessSpecifier] dataType Name;
AccessSpecifier ' modifier 4 ! public, protected, private, default dataType "# " $ % Attribute &' int , char Name & Attribute & ! "
[AccessSpecifier] return_type Name([arguments]){ Method body }
AccessSpecifier ' modifier Method 4 ! public, protected, private, default return_type ( ) (3$ / $% ( method $ ( 4! Name - Method ! ( (- get , set arguments ( ) . 0 ( 0$,% - / ( / method !! & % 4&
Static Method â—Ś Method $% % Static ' ( % ,- & ( + & Object
Instance Method â—Ś Method $% & % Static ' Object ! ( % ,- Method &
Overloading Method â—Ś Method ' 2 Method $% %- (' . %! ' - " ( 0
( ) Method $% ( % ,- & + & Object (- %$% / , Class ( % ( % ,- - Method * & ( public class SimpleMethod { // 5 ( + .
public static void main(String[] args) //( 6 ' { System.out.println("Hello from the main method."); displayMessage();
//( % ( 6 displayMessage() $% *
System.out.println("Back in the main method."); } public static void displayMessage() //( 6 ,' $% * { System.out.println("Hello from the displayMessage method."); } }
public class LoopCall{ public static void main(String[] args) { System.out.println("Hello from the main method."); for (int i = 0; i < 5; i++)// / / ( % ( 6 $% * $ 5 *
displayMessage(); System.out.println("Back in the main method."); } public static void displayMessage() //( 6 $% * { System.out.println("Hello from the displayMessage method."); } }
%$% / Class ( % ,- - Class ! . . - Method public class LoopCall{ public static void main(String[] args) { System.out.println("Hello from the main method."); for (int i = 0; i < 5; i++) // / ( % ( 6 $% * $ 5 * LoopMethod.displayMessage(); System.out.println("Back in the main method."); } } class LoopMethod{ public static void displayMessage() //( 6 $% * { System.out.println("Hello from the displayMessage method."); } }
, void ' - method Method & . & % parameter public void displayMessage(){ System.out.println(â&#x20AC;&#x153;Helloâ&#x20AC;?); }
Method & . % parameter public void welcome(Srting name){ System.out.println(â&#x20AC;&#x153;Hello â&#x20AC;? +name ); }
, (3$ / $% $% ' - method . , return $% , $ $ method Method . & % parameter ,- , Attribute public double getLength(){ return length; }
Method . % parameter public int add(int x,int y){ return x+y; }
public class Rectangle{ private double length; private double width;
Data Member (Attribute) Method Member
public void setLength(double len){ length = len; } } class Sawasdee{ String data="Sawasdee "; public void show(String s){ System.out.println(data+s); } }
Data Member (Attribute)
Method Member
Object ! $ & . %* 6%$% 1. ' - Object . ! Object ClassName ObjectName; ObjectName = new ClassName([arguments]); Rectangle box ; box = new Rectangle();
6%$% 2. ' - Object " Object ClassName ObjectName = new ClassName([arguments]); Rectangle box = new Rectangle();
Object box Rectangle Reference Rectangle $% - box Rectangle box ; box adress
' ,' Reference $% - box ,' -%*& Object Rectangle box = new Rectangle(); box
length :0.0
adress
Object Rectangle
Width:0.0 setLength setWidth getLength getWidth getArea
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/ . - . ( ' ! . . - ObjectName.AttributeMember; // Atrribute ObjectName.MethodMember();
// Method
(- ( % ,- Method setLength() Object box box.setLength(10.0);
box.setLength(10.0); box.setWidth(5.5); Object Rectangle box
length length:10.0 :0.0
adress
Width:0.0 Width:5.5 setLength setWidth getLength getWidth getArea
public class Rectangle{ private double length; private double width; public void setLength(double len){ // length = len; // } public void setWidth(double w){ // width = w; } public double getLength(){ // return length; // ! } public double getWidth(){ // return width; } public double getArea(){ // "!# $%& return length * width; // ! "!# $%& } }
public class RectangleDemo { public static void main(String[] args) { Rectangle box = new Rectangle();// (!4 0- box ,' ( ) % (' %
box.setLength(10.0); // ' box box.setWidth(20.0); // ' box System.out.println("The box's length is " + box.getLength());//. 9 box System.out.println("The box's width is " + box.getWidth());//. 9 box System.out.println("The box's area is " + box.getArea());//. " * $% box } }
class CalScore{ // calscore public void calculate(){ //( 6 ' ' ( double score = Math.random()*100; // . ' 0 100 if (score >= 80){ // . 80 System.out.println("Grade is A"); //& ( A }else if (score >= 70){ // & 80 . ' ($ 70 System.out.println("Grade is B"); //& ( B } else{
//' ( ) . 2 System.out.println("Grade is C"); //& .
} }
} //! CalScore
//! ( 6 ' ' (
public class CalGrade{ //( 6 + . ' public static void main(String args[]){ CalScore obj = new CalScore(); // (!4 0- obj CalScore obj.calculate(); //( % ,- ( 6 calculate } }