java programming part 1.pdf

Prepared by: Mr. HIEENG Sokh Hymns - 1 -

Java Programming

Java Q: Java ? A: Java (Program) (www.sun.com) Q: C++ ? A: C++ Concepts Java

1. Install JDK (Java Development Kit) Compiler Java 2. Install NetBeans File Code File NetBeans Versions

JDK and NetBeans 6.8 Version 6.8 File Programmer Java File JDK NetBeans File

JDK and NetBeans 6.9 Version 6.9 2 Files File JDK File NetBeans 6.9 (www.netbeans.org) Download last version free


Chapter 1

Datatype and Variable

Datatype C++ Java 1.

Datatype C++ char, short, int, long, float, double, long double Datatype Java

1. Integer number : Datatype byte, short, int, long 2. Floating-point number : Datatype float, double 3. Character : Datatype char 4. Boolean : Datatype True False Boolean

1.1. Integer number

Datatype Size Range

byte 1 byte - 128 to 127

short 2 bytes - 215

to 215 1

int 4 bytes - 231

to 231 1

long 8 bytes - 263

to 263 1

1.2. Floating-point number

Datatype Size Range

Float 4 bytes 3.4e-38 to 3.4e+38

Double 8 bytes 1.7e-308 to 1.7e+308

Q: 3.4e+38 ? A: 3.4e+38 3.4 x 1038 Q: Logo Java ? A: James Gosling Java


1.3. Character

Datatype Size Range

char 2 bytes 0 to 65, 536 Java Support Fonts , , ...

1.4. Boolean

Datatype Size Range

boolean 1 byte true or false

boolean b; Keyword Variable b = true;

System.out.print(b = +b);

// b = true

Output Console

Q: True or False ? A: True or False

C++ int a;

a = 2;

cout


String Java Variable String Class String

String stName;

stName = Sok Rotha;

System.out.print(Hi!, +stName);

String st1 = Java;

String st2 = Programming;

String st = st1 + +st2;

System.out.print(st = +st);

// st = Java Programming

String

String a = 1;

String b = 2;

String sum = a + b; System.out.print(Sum = +sum);

// Sum = 12

Ctrl + R = Ctrl + Space = Shift + F6 = Run Java

2. (Variables)

Java Variable a z A Z 0 9 Underscore ( _ )


int age;

long ID;

float price;

char ch1;

double total_price;

Initialization of variable Variable

int age=18; Initialization

int age; Declaration

age=18; Assignment ( C++ 100%) float

double x = 2.5; x = 2.5;

float y = 2.5f; y = 2.5f;

float


Chapter 2

Control Statement

1. Overview

Java Control Statement 3 1. Selection Statements Statement Statement execute if-else, switch

2. Loop Statements Statement execute while, do while for

3. Jumping Statements Statement execute Statement break continue

2. Selection Statement

2.1. if-else

statement statement if statement if execute statement else execute

= Form : if(condition){

statement(s);

}else{

Statement(s);

}

int a = 0;

if(a>0)

System.out.print(A is positive.);

else if(a


2.2. switch

Switch statement statement Statement Execute

Form: switch (expression){

case value1:

statement(s);

case value2:

statement(s);

case value3:

statement(s);

default:

statement(s);

}

char ch = R;

switch(ch){

case R:

System.out.print(Red); break;

case G:

System.out.print(Green); break;

case B:

System.out.print(Blue); break;

Defaut:

System.out.print(Unknown color);

}

char ch = R;

switch(ch){

case R: case r:

System.out.print(Red); break;

case G: case g:

System.out.print(Green); break;

case B: case b:

System.out.print(Blue); break;

Defaut:

System.out.print(Unknown color);

}


3. Loop Statement

execute statement 3.1. while

Loop execute statement Form :

while(condition){

statement(s); }

int i = 1;

while(i=1){

System.out.print(i + , );

i--;

}

// 5, 4, 3, 2, 1,

3.2. do while

Loop execute statements

Form:

do{

statements;

}while(condition);

int i = 1;

do{

System.out.print(i + , ); i++;

}while(i


int i = 5;

do{


i--;

}while(i>=1);

3.3. for Loop Loop Expression 3 statements statements 3

Initialization: Statement Loop statement execute Loop

Condition: Statement Loop Step: Statement Loop Form:

for(initialization; condition; step){

statements;

}

for(int i=1; i=1; i--)


// 5, 4, 3, 2, 1,

4. Jumping statement statement execute statement 4.1. Break statement statement switch Loop for(int i=1; i


4.2. Continue statement statement 1 Loop

for(int i=1; ib)

System.out.print(Maximum is +a);

Else

System.out.print(Maximum is +b);

}

}


Chapter 3

Array

Q. What is array?

A. Array Variables Datatype Index

1. One dimensional array

One dimensional array Array Datatype arrayName[ ] = new Datatype[elements];

a[0] a[1] a[2] a[3] a[4]

a array a [ ]

Java array n elements Variable int n;

n=cin.nextInt();

int a[]=new int[n];

import java.util.Scanner;

public class InputArrayN{

public static void main(String arg[]){

Scanner cin=new Scanner(System.in);

int n;

System.out.print(Enter n = );

n=cin.nextInt();

int a[]=new int[n];

System.out.println(Now, you can enter +n+ values);

for(int i=0; i


System.out.print(Enter a[+i+] = );

a[i] = cin.nextInt();

}

System.out.println(Now, you can display +n+ values);

for(int i=0; i



public class Main{



int n;

System.out.print(Enter number of elements = );

N=cin.nextInt();

int a[]=new int[n];

System.out.println(Now, you can enter +n+ values);

for(int i=0; i


for(int i=0; i


System.out.println(Enter a[+i+] = );

boolean b=false;

int value;

value=cin.nextInt();

for(int j=0; j



public class InputArray2{



int r, c;

System.out.print(Enter rows = );

r=cin.nextInt();

System.out.print(Enter columns = );

c=cin.nextInt();

int a[][]=new int[r][c];

for(int i=0; i


System.out.println(Enter a[+i+] = );

a[i]=cin.nextInt();

}

int temp[];

temp=a;

int m;

System.out.print(Enter m = );

m=cin.nextInt();

a=new int[n+m];

for(int i=0; i


Chapter 4

Introduction to Class

1. Overview

Class Instances variables Methods Instances variables Methods Members Class

2. Class Fundamentals

2.1. The General form of Class

Class ClassName{

DataType InstanceVariable;

returnType methodName(arg){

//body

}

}

Class Rectangle{ Class

double w;

double n;

double parameter(){ Instance variable

return (w+n)*2;

}

double are(){

return w*n; Method

}

}

Instance variable Variable Class Variable Class variable class

Method Function Class Method Class


2.2. Execute member of Class

Execute Member Class Object Class Object Member Class

Form:

ClassName ObjectName = New ClassName();

Retangle obj = new Rectangle();

public class Main{

public static void main(string arg[]){

Rectangle obj=new Rectangle();

obj.h = 10;

obj.w = 20;

System.out.println(Parameter = +obj.parameter());

System.out.println(Area = +obj.area());

}

}

3. Method

3.1. Method has return type Method return type double, long, int, ... Method return statement

3.2. Method has not return type Method return type void Method return statement

public class SubProgram{

double max(double a, double b){

if(a>b)

return a;

else

return b;

}

void showStars(int n){

for(int i=1; i


Practice

User Interface ( Code + Design) 1. Right-Click on Package new Jframe Form Finish 2. Click F6 to run form

3. Click Palette to Design form

UserName:

Password:

4. Click on Frame Property Code

5. Exit (cmdExit) System.exit(0); ( exit ) 6. Font click on Label Property Font 7. Logo : Label Right-Click Property Icon 8. Background Frame Label Frame

Menu bar (Open Project D:\SH5) 1. Right-Click on Package New JFrame Form Finish 2. Palette ( Tool) Swing Menu Menu bar Project 3. Right-Click on Menu Edit Text Variable Name (cmdFile, cmdEdit, ...)

4. Code Exit Right-Click on Exit Event 5. Menu Right-Click on Mouse Menu

Add Menu

6. File Menu Menu Add from palette Menu Item

7. Code Exit Right-Click on Exit Event Action Performed cmdExit System.exit(0);

8. File, Edit . Menu Menu item Navigate Inspect File Member

txtUsername

txtPassword

Bottom Log In Exit


19/Feb/2011

4. Constructors

Method Class Method execute Object Class Constructor Initialize Member Class

Create object

ClassName ObjectName = New Constructor();

Rectangle Object = new Constructor(); Member Class

public class Boxes{

double w, h, d;

public Boxes(){

w = 10;

h = 10;

d = 10;

}

double area(){

return w*h*d;

}

}

public class MainBox{


Boxes obj=new Boxes();

System.out.println (width = +obj.w);

System.out.println (height = +obj.h);

System.out.println (depth = +obj.d);

System.out.println (area = +obj.area());

}

}


Overloaded constructors: Constructor Class Constructors Argument DataType Arguments

public class Boxes{

double w, h, d;

public Boxes(){

w = 10;

h = 10;

d = 10;

}

public Boxes(double width, double height, double depth){

w = width;

h = height;

d = depth;

}

double area(){

return w*h*d;

}

}



Boxes obj1=new Boxes();

System.out.println (width = +obj1.w);

System.out.println (height = +obj1.h);

System.out.println (depth = +obj1.d);

System.out.println (area = +obj1.area());

System.out.println (.);

Boxes obj2=new Boxes(5,5,5);

System.out.println (width = +obj2.w);

System.out.println (height = +obj2.h);

System.out.println (depth = +obj2.d);

System.out.println (area = +obj2.area());

}

}


Overloaded constructor initialize Object

5. this keyword: keyword Current object Member Class

public class Boxes{

double w, h, d;

public Boxes(double w, double h, double d){

this.w = w;

this.h = h;

this.d = d;

}

}

6. Object and Array

object array array object constructor

Boxes obj1;

obj1.w = 6 // cant use

Boxes obj[] = new Boxes[2];

// obj[0].w = 1; cant use

obj[0] = new Boxes();

obj[1] = new Boxes(5,5,5);

obj[0].w = 1; // can use

public class Student{

long id;

string name;

char gender;

string address;


public Student(long id, string name, char gender, string address){

this.id = id;

this.name = name;

this.gender = gender;

this.address = address;

}

}


public class TestArray{

public static void mani(String arg[]){


int n;

System.out.print(Enter n = );

n=cin.nextInt();

Student obj[]=new Student[n];

long id; string name; char gender; string address;

for(int i=0; i


System.out.print(obj[i].address + \t);

System.out.println(____________________);

}

}

}

12 March, 2011

Object Array Record Records Records Field

ID long PName String Qty long UPrice float Amount double (Not input by user)

public class Product{

long id;

string pname;

long qty;

float uprice;

double amount;

public Product(long id, string pname, long qty, float uprice){

this.id = id;

this.pname = pname;

this.qty = qty;

this.uprice = uprice;

this. amount = qty*uprice;

}

}


Import jave.util.Scanner;

Public class MainProduct{

Public static void main(String arg[]){


int n;

System.out.print(Enter number of records = );

n=cin.nextInt();

Product obj[]=new Product[n];

long id; string pname; long qty; float uprice;

for(int i=0; i


Homework:

N Records Students Records Field

ID long SName String Gender String Address String Year int Class String Java float Acc float C++ float AVG double (Not input by user) AVG () public class Student{

long id;

string sname;

string gender;

string address;

int year;

string class;

float java, acc, cpp;

double avg(){

return(java+acc+cpp)/3;

}

Student copy(){

Student temp=new Student(id, sname, gender, address, year, Class, java, acc,

cpp);

return temp;

}

public Student(long id, string sname, string gender, string address, int year, string

class, float java, float acc, float cpp){

this.id = id;


this.sname = sname;

this.gender = gender;

this.address = address;

this.year = year;

this.class = class;

this.java = java;

this.acc = acc;

this.cpp=cpp;

}

}

import java.text.DecimalFormat;

import java.util Scanner;

pubic class ArrayObj{



int n;

System.out.print(Enter number of Records = );

n=cin.nextInt();


long id; string sname; string gender; string address, int year; string class; float

java; float acc; float cpp;

for(int i=0; i


System.out.print(Enter CLass = );

cin.nextLine();

CLass=cin.nextLine();

System.out.print(Enter Java = );

java=cin.nextFloat();

System.out.print(Enter Access =);

acc=cin.nextFloat();

System.out.print(Enter C++ = );

cpp = cin.nextFloat();

obj[i]=new Student(id, sname, gender, year, class, java, acc, cpp);

System.out.println(AVG = +obj[i].avg);

System.out.println(______________________________________\n);

}

System.out.println(\n__________________________________________\n);

System.out.println(ID\tStudentName\t\tGender\tYear\tClass\tJava\tAcc

\tC++\tAVG\n);

for(int i=0; i


System.out.print(df.format(obj[i].avg())+ \t);

System.out.print(\n______________________________________\n);

}

}

}

20/March/2011

Referenct Object

Object Object Object Reference Referent Object Object Object Address Object Object



Obj1=obj2; // Referent Object

Referent Object Object Object Initialize Constructor Object Referent Object

Return Object

Method Return Type Class Return value Object Class Return Object Object Object Object Referent Object public class Boxes{

double w;

double h;

double d;

Boxes copy(){ // Return object

Boxes temp=new Boxes(w, h, d);

Return temp;

}


public Boxes(){

w=10;

h=10;

d=10;

}

public Boxes(double w, double h, double d){

this.w=w;

this.h=h;

this.d=d;

}

double area(){

return w*h*d;

}

}





// obj1=obj2; // Referent Object

/*

obj1.d=obj2.d;

obj1.h=obj2.h; obj1.w=obj2.w; */

obj1.d=obj2.copy(); // Not Referent Object

obj2.d=1;

obj2.h=1;

obj2.w=1;

System.out.println(Width = +obj1.w);

System.out.println(Height = +obj1.h);

System.out.println(Depth = +obj1.d);

System.out.println(_______________________);

}

}


Runnable Class Runnable

Thread Class Runnable Runnable

7. ArrayList Class Package Java.util.ArrayList n records ArrayObject

Form:

ArrayList obj=new ArrayList();

Ex: // ArrayList

ArrayList obj=new ArrayList();

Ex: // ArrayObject


Method in ArrayList

boolean add(Object record); Method add object record ArrayList Record add Record Index Record add index

object set(int index, object record); Method Record index ArrayList ( 1 Record)

object get(int index); Method Record ArrayList Index

int size(); Method Record ArrayList boolean remove(object record); Method Remove record ArrayList Record


Chapter 5

More on Class

Method Arguments Objects Arguments Parameters Objects

Sub-program

public class Product{

long id;

string pname;

long qty;

float uprice;

double amount(){

return qty*uprice;

}

boolean equal(Product obj){

if(obj.id==id&&obj.paname.equals(pname)&&obj.qty==qty&&obj.uprice==

uprice)

return true;

else

return false;

}

public Product(long id, string pname, long qty, float uprice){

this.id=id;

this.pname=pname;

this.qty=qty;

this.uprice=uprice;

}

}

Main-program

public class Mproduct{

public static void main(String[] args){

Product obj1=new Product(1, ABC, 200, 23);

Product obj2=new Product(1, ABC, 200, 23);


if(obj1.equal(obj2))

System.out.println(The same record.);

else

System.out.println(Not the same record.);

}

}

1. Overview 2. Parameter passing

Parameter Arguments Pass by value Pass by reference 1.1. Pass by value ( C++)

Sub-program

public class Data{

void changeValue(int a, int b){

a+=2;

b+=4;

}

}

Main-program

public class main{


int a, b;

a=10;

b=10;

obj.changeValue(a, b); // Pass by value

System.out.println(A = +a);

System.out.println(B = +b);

}

}

1.2. Pass by reference ( C++) Sub-program

public class Data{

int a, b;

void changeValue(Data obj){


obj.a+=2;

obj.b+=4;

}

}

Main-program

public class main{


Data obj=new Data();

obj.a=10;

obj.b=10;

obj.changeValue(obj); // Pass by reference

System.out.println(A = +obj.a);

System.out.println(B = +obj.b);

}

}

Parameter Variable Pass by value Parameter object Array Pass by reference

3. Static keyword ( C++) Keyword Members Class Member Address

Address Object

Sub-program

public class Data{

static int a;

int b;

}

Main-program

class Main{


Data obj1=new Data();


// All members can use object(Static or non-static)

obj1.a=1;

obj2.b=1;

// Static members can use without object

Data.a=10;

// Non-static member cannot use without object

// Data.b=10;

Data obj2=new Data();

// All objects use the same static members

Obj2.a=20;

System.out.println(A = +obj1.a);

System.out.println(A = +obj2.a);

System.out.println(A = +Data.a);

}

}

Static keyword Global variable Global variable Java Variable Class Class Package Package


Chapter 6

Inheritance

1. What is inheritance?

Inheritance Class Class SuperClass Class Member Class SubClass Class Member Class

2. Inheritance

Form: public inheritance

class SubClass entends SuperClass{

// Member SubClass

}

class SuperClass{

int a, b;

}

class Sub extends SuperClass{

int c;

}

3. Using super keyword 3.1. super keyword call Constructors of SuperClass

class SuperClass{

int a, b;

public SuperClass(int a, int b){

this.a=a;

this.b=b;

}

}


int c;

public Sub(int a, int b, int c){


Super(a, b);

this.c=c;

}

}

3.2. super keyword call Member SuperClass

class SuperClass{

int a, b;

void show(){

System.out.println(A = +a);

System.out.println(B = +b);

}

public SuperClass(int a, int b){

this.a=a;

this.b=b;

}

}


int c;

void show(){

System.out.println(C = +c);

}

public Sub(int a, int b, int c){

Super(a, b);

this.c=c;

}

}

4. Method overriding

Overloaded method Method SubClass Arguments Method SuperClass


class Star{

void show(){

for(int i=1; i


obj.show();

obj.show(10);

obj.show(20, @);

}

}

Overloaded VS Override

1. Method Argu-ments DataType Arguments

2. Overloaded method Object Class Method Arguments

3. Overloaded Method SuperClass SubClass

1. Method Arguments DataType Arguments

2. Overrided Method Object Class Method Class

3. Overrided method SubClass

08 May 2011

5. Abstract class

Abstract class class method Abstract class can refer with other SubClass

abstract class AbSimple{

void show(){

System.out.println(You can call me.);

}

abstract void show(String txt);

}

class Sub extends AbSimple{

void show(String txt){

System.out.println(txt);

}


}

public class Main{


AbSimple obj=new AbSimple(){

// @override


Systme.out.println(txt);

}

};

obj.show(Just override);

Sub obj2=new Sub();

Obj2.show();

}

6. Using final keyword

6.1. Using final keyword to prevent overriding

abstract class AbSimple{

abstract void show(String txt); // Must override

final void show(){

System.out.println(Cannot override at SubClass.);

}

void show (String txt, int n){

System.out.println(txt+ +n);

System.out.println(Can or cannot override.);

}

}

class Sub extends AbSimple{


System.out.println(txt);

}

}

public class Main{



AbSimple obj=new AbSimple(){

// @override


Systme.out.println(txt);

}

};

obj.show(Just override);

Sub obj2=new Sub();

Obj2.show();

}

java programming part 1.pdf

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