javamodule01

8/7/2019 JavaModule01

1/61

Introduction


2/61


3/61

Code:

#include

void main()

{

printf("Hello World");

}

Output:

Hello World


4/61

Code:

#include

void main()

{

cout


5/61

Compilation refers to the processing

of source code files (.c, .cc, or .cpp)

and the creation of an 'object' file.

Linking refers to the creation of asingle executable file from multiple

object files.


6/61

#include

class Hello

{

public:

void displayHello()

{

cout


7/61

Code:

class Hello

{

public static void main(String args[])

{

System.out.println(Hello World.");

}

}

Output:

Hello World


8/61

Download and install the latest Java

SDK (S/W Dev. Kit) from

http://java.sun.com.Set the ENVIRONMENT

set path=c:\j2sdk1.4.1_01\bin

[Command Prompt (cmd)]

Start > Settings > Control Panel > System> Advanced > System Variables > Path

(c:\j2sdk1.4.1_01\bin)


9/61

To compile the Hello program,

execute the compiler, javac,

specifying the name of the sourcefile on the command line, as shown

here:

Z:\Java> javac HelloWorld.java


10/61

To run the program, you must use

the Java interpreter, called java. To

do so, pass the class name Hello as acommand-line argument, as shown

here:

Z:\Java> java Hello


11/61


12/61

In 1990, Sun Microsystems begana project called Green for

developing a software for theconvergence of digitallycontrolled consumer devices andcomputers.

Patrick Naughton, MikeSheridan, and James Gosling Project Members.


13/61

The Green software ran on an

entirely new, processor-

independent language.Gosling called the new language

"Oak," after the tree outside his

window.In 1995 Oak was renamed to

Java.


14/61

Bytecode is a highly optimized set of

instructions designed to be executed

by the Java run-time system, which

is called the Java Virtual Machine

(JVM).

JVM is an interpreter for bytecode.

JIT compiler is part of the JVM, it

compiles bytecode into executable

code in real time, on a piece-by-

piece, demand basis.


15/61

15


16/61

16


17/61

You write

Java codeusing an

editor

javac MyProg.java

java MyProg

Java code:

MyProg.java

Bytecode:

MyProg.class

Text Editor

Output

You save

the file

with a .java

extension

You run theJava

compiler

'javac'

You execute

the bytecode

with the

command 'java'

This createsa file of

bytecode

with a.class

extension

17


18/61

Java can be used to create two

types of programs: applications

and applets.An application is a programthat runs on your computer,

under the operating system ofthat computer.

18


19/61

An applet is an applicationdesigned to be transmitted over

the Internet and executed by aJava-compatible Web browser.

An applet is actually a tiny Javaprogram, dynamically

downloaded across the network,just like an image, sound file, orvideo clip.

19


20/61

You write

Java codeusing an

editor

javac MyApp.java

appletviewer

MyApp.html

Java code:

MyApp.java

Bytecode:

MyApp.class

Text Editor

Window

You save the

file with a.java

extension

You run the Java

compiler 'javac'

You can view the applet

with the command

'appletviewer'

This creates a file

of bytecode with a.class extension

Web page:MyApp.html

Text Editor

Web

Browser

You write a

web page inhtml using

an editor

You can view the web

page from a webbrowser

You save the

file with a

.html

extension

20


21/61


22/61

Simple

Secure

PortableObject-oriented

Robust (The degree towhich a system or

component can functioncorrectly in the presence of

invalid inputs or stressful

environmental conditions.)

Multithreaded

Architecture-

neutral

Interpreted

High performance

Distributed

Dynamic


23/61

OOP Principles

Encapsulation

Inheritance

Polymorphism Two Paradigms - code and data

Process - oriented programming - code

acting on data

Object - oriented programming - datacontrolling access to code

23


24/61

Whitespace: space, tab, newline

Identifiers: case-sensitive (class names,

variables)

Comment

Single line: //

Multi line: begin with /* and end with */

Documentation: begin with /** and end with */

Literals - a constant value

Separators - () {} [] ; , .

24


25/61


26/61


27/61

Integers: This group includes byte, short,int, and long, which are for whole valuedsigned numbers.

F

loating-point numbers :This group includesfloat and double, which represent numberswith fractional precision.

Characters This group includes char, whichrepresents symbols in a character set, like

letters and numbers. Boolean: This group includes boolean, which

is a special type for representing true/falsevalues.

27


28/61

28

Name Width

long 64

int 32

short 16

byte 8


29/61

29

Name Width

double 64

float 32


30/61

In Java char is a 16-bit type

The range of a char is 0 to 65,536

Java uses Unicode to representcharacters

Unicode defines a fullyinternational character set that can

represent all ofthe characters

found in all human languages.

30


31/61

Escape Sequence Description

\ddd Octal character (ddd)

\uxxxx Hexadecimal UNICODE character(xxxx)

\ Single quote

\ Double quote

\\ Backslash

\r Carriage return

\n New line (also known as line feed) \f Form feed

\t Tab

\b Backspace

31


32/61


33/61

class Scope {

public static void main(String args[]) {

int x; // known to all code within main

x = 10;

if(x == 10) { // start new scopeint y = 20; // known only to this block

// x and y both known here.

System.out.println("x and y: " + x + " " + y);

x = y * 2;

}

// y = 100; // Error! y not known here

// x is still known here.

System.out.println("x is " + x);

}

}

33


34/61

When one type of data is assigned to another

type of variable, an automatic typeconversion will take place if the following

two conditions are met: The two types are compatible.

The destination type is larger than the

source type.

When these two conditions are met, awidening conversion takes place.

34


35/61

To create a conversion between two

incompatible types, you must use a cast. A

cast is simply an explicit type conversion. It

has the general form:(target-type) valueHere, target-type specifies the desired type

to convert the specified value to.

int a;

byte b;

b = (byte) a;

35


36/61

byte b = 50;

b = b * 2; // Error! Cannot assign an int to a

byte!

The intermediate term b * 2 easilyexceeds the range of either of its byte

operands. To handle this kind of problem,

Java automatically promotes each byte or

short operand to int when evaluating anexpression.

byte b = 50;

b = (byte)(b * 2);

36


37/61

One-Dimensional Arrays

type var-name[ ];

int month_days[];

array-var = new type[size];

month_days = new int[12];

int month_days[] = new int[12];

37


38/61

Multidimensional Arrays

int twoD[][] = new int[4][5];

int twoD[][] = new int[4][ ];

twoD[0] = new int[1];

twoD[1] = new int[2]; twoD[2] = new int[3];

twoD[3] = new int[4];

38


39/61

double m[][] = {

{ 0, 1, 2, 3 },

{ 0, 1, 2, 3 },{ 0, 1, 2, 3 },

{ 0, 1, 2, 3 }

};

39


40/61

type[ ] var-name;

int al[] = new int[3];int[] a2 = new int[3];

40


41/61


42/61


43/61

++ Increment

+= Addition assignment

= Subtraction assignment

*= Multiplication assignment

/= Division assignment

%= Modulus assignment

Decrement

43


44/61

~ Bitwise unary NOT

& Bitwise AND

| Bitwise OR

^ Bitwise exclusive OR

>> Shift right

>>> Shift right zero fill


45/61

&= Bitwise AND assignment

|= Bitwise OR assignment

^= Bitwise exclusive OR assignment

>>= Shift right assignment

>>>= Shift right zero fill

assignment


46/61

== Equal to

!= Not equal to

> Greater than

< Less than

>= Greater than or equal to


47/61

& Logical AND

| Logical OR

^ Logical XOR (exclusive OR)

|| Short-circuit OR

&& Short-circuit AND

! Logical unary NOT

47


48/61

&= AND assignment

|= OR assignment

^= XOR assignment

== Equal to

!= Not equal to

?: Ternary if-then-else

48


49/61


50/61


51/61

If

if (condition) statement1;

else statement2;

Nested ifs A nestedif is an if statement that is the target

of another if or else.

51


52/61

if-else-if Ladder

if(condition)

statement;

else if(condition)statement;

else if(condition)

statement;

...else

statement;

52


53/61

switch (expression) {

case value1:

// statement sequence

break;

case value2:// statement sequence

break;

...

case valueN:

// statement sequencebreak;

default:

// default statement sequence

}

53


54/61

switch(count) {

case 1:

switch(target) { // nested switch

case 0:

System.out.println("target is zero");

break;

case 1: // no conflicts with outer switch

System.out.println("target is one");

break;}

break;

case 2: // ...

54


55/61

The switch differs from the if in that switch

can only test for equality, whereas ifcanevaluate any type of Boolean expression.

That is, the switch looks only for a matchbetween the value of the expression and one

of its case constants.

55


56/61

No two case constants in the same switch

can have identical values. Of course, aswitch statement enclosed by an outer

switch can have case constants in common. A switch statement is usually more

efficient than a set of nested ifs.

56


57/61

while loop

while(condition) {

// body of loop

} do-while loop

do {

// body of loop

} while (condition)

57


58/61

for

for(initialization; condition; iteration) {

// body

}Declaring Loop Control Variables Inside the

for Loop

Using the Comma

Nested Loops

58


59/61

Java supports three jump statements: break,continue, and return.

59


60/61

class Break {

public static void main(String args[]) {

boolean t = true;

first: {

second: {

third: {System.out.println("Before the break.");

if(t) break second; // break out of second block

System.out.println("This won't execute");

}

System.out.println("This won't execute");

}

System.out.println("This is after second block.");

}

}

}

60


61/61

Thank You !!!

javamodule01

Documents