Download to read offline
![Encapsulation: Example
Book Borrower
Title
Author
Accession No.
Cost
Borrower DOI
Issue()
Fine()
Return()
Open()
Close()
data
methods
Name
Roll No.
Address
Marks
Books[]
Search Books()
Request()
Renew()
Enroll()
Exit()
data
methods](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-19-2048.jpg)
![Program in C and Java
#include <stdio.h>
int main()
{
printf("Hello, World!");
return 0;
}
import java.lang.*;
class HelloWorldApp
{
public static void main(String args[]){
System.out.println("Hello, World!");
}
}
A program in C to display message A program in Java to display message
Note: Both the languages are case sensitive](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-32-2048.jpg)
![The Java character set
•The Java language alphabet
•Uppercase letters ‘A’ to ‘Z’
•Lowercase letters ‘a’ to ‘z’
•Digits ‘0’ to ‘9’
•Java special characters:
, < > . _
( ) ; $ :
% [ ] # ?
' & { } "
^ ! * / |
- ~ +](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-66-2048.jpg)
![Declaration of array
<type> <arrayName>[ ];
Example:
int x[ ];
<type>[ ] <arrayName>;
Example:
int [ ] x;
Creating an array
Allocate memory for an array
<arrayName> = new <type> [<size>];
Example:
x = new int [100 ];](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-71-2048.jpg)
![Define and allocate memory together
<type> <arrayName> [ ] = new <type> [<size>];
Example:
int x [ ] = new int [100];
Creating an array](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-72-2048.jpg)
![Initialization of Array
<arrayName> [<subscript> ] = <value>;
Example:
x [5] = 100;
for (int i = 0; i < 100; i++)
x[i] = <value>;
Storing elements in array](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-73-2048.jpg)
![Initialization of array: An alternative way
<type> <arrayName> [ ] = { <list of values> };
Example:
int x [ ] = {12, 3, 9, 15};
Storing elements in array
Here, declaration, allocation of memory and array initialization all are at one go!](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-74-2048.jpg)
![• Declaration of an array
Examples
int numbers[ ];
float averageScores[ ];
int [ ] rollNo;
float [ ] marks;
• Memory allocation for an array
Examples
numbers = new int [5];
averageScores = new float [20];
rollNo = new int [49];
marks = new float [54];
• Initialization of an array
Examples
int numbers[] = {5, 4, 2, 1, 3};
float marks[] = {2.5, 3.4, 4.5};
What is the size of the array marks?
n = marks.length;
How to define a two dimensional array?
Array in Java: A quick visit](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-76-2048.jpg)
![Declare and Allocate
Example:
int myArray [ ] [ ];
myArray = new int [3] [4];
OR
int myArray [ ] [ ] = new int [3] [4];
Creating a 2D array](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-77-2048.jpg)
![Initializing a 2D array : An example
int myArray [2] [3] = {1, 2, 3, 4, 5, 6};
OR
int myArray [ ] [ ] = { {1, 2, 3}, {4, 5, 6} };
1
6
5
4
3
2
Loading a 2D array](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-78-2048.jpg)
![ Creating a variable-sized 2D array
<type><2DarrayName>[][] = new <type> [<rowSize>][];
for (int i = 0; i < <rowSize>; i++)
<2DarrayName>[i] = new <type> [<colSizei>];
x[0]
x[1]
x[2]
Variable sized 2D array
Another way: Example
int x [ ] [ ] = new int [3][ ];
x[0] = new int [2];
x[1] = new int [4];
x[2] = new int [3];](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-79-2048.jpg)
![3D arrays : An example
class a3DArray {
public static void main(String args[]) {
int my3DArray [ ][ ][ ] = new int [3][4][5];
int i, j, k;
for(i=0; i<3; i++)
for(j=0; j<4; j++)
for(k=0; k<5; k++)
my3DArray[i][j][k] = i * j * k;
for(i=0; i<3; i++) {
for(j=0; j<4; j++) {
for(k=0; k<5; k++)
System.out.print(my3DArray[i][j][k] + " ");
System.out.println();
}
System.out.println();
}
}
}](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-80-2048.jpg)
![Example program using an array
class TestArray{
public static void main(String args[]){
int a[] = new int[5]; //Declaration and instantiation
a = {10, 20, 30, 40, 50}; //Initialization
//Traversing array
for(int i=0;i<a.length;i++){ //length is the property of array
System.out.println(a[i]);
}
// Average calculation
float sum = 0; avg;
for(i=0;i<a.length;i++) //Calculating the sum of the numbers
sum += a[i];
avg = sum/a.length;
System.out.println(“Avergae = “ + avg);
}
}](https://image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-81-2048.jpg)
![Encapsulation: Example
Book Borrower
Title
Author
Accession No.
Cost
Borrower DOI
Issue()
Fine()
Return()
Open()
Close()
data
methods
Name
Roll No.
Address
Marks
Books[]
Search Books()
Request()
Renew()
Enroll()
Exit()
data
methods](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-19-2048.jpg)
![Program in C and Java
#include <stdio.h>
int main()
{
printf("Hello, World!");
return 0;
}
import java.lang.*;
class HelloWorldApp
{
public static void main(String args[]){
System.out.println("Hello, World!");
}
}
A program in C to display message A program in Java to display message
Note: Both the languages are case sensitive](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-32-2048.jpg)
![The Java character set
•The Java language alphabet
•Uppercase letters ‘A’ to ‘Z’
•Lowercase letters ‘a’ to ‘z’
•Digits ‘0’ to ‘9’
•Java special characters:
, < > . _
( ) ; $ :
% [ ] # ?
' & { } "
^ ! * / |
- ~ +](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-66-2048.jpg)
![Declaration of array
<type> <arrayName>[ ];
Example:
int x[ ];
<type>[ ] <arrayName>;
Example:
int [ ] x;
Creating an array
Allocate memory for an array
<arrayName> = new <type> [<size>];
Example:
x = new int [100 ];](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-71-2048.jpg)
![Define and allocate memory together
<type> <arrayName> [ ] = new <type> [<size>];
Example:
int x [ ] = new int [100];
Creating an array](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-72-2048.jpg)
![Initialization of Array
<arrayName> [<subscript> ] = <value>;
Example:
x [5] = 100;
for (int i = 0; i < 100; i++)
x[i] = <value>;
Storing elements in array](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-73-2048.jpg)
![Initialization of array: An alternative way
<type> <arrayName> [ ] = { <list of values> };
Example:
int x [ ] = {12, 3, 9, 15};
Storing elements in array
Here, declaration, allocation of memory and array initialization all are at one go!](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-74-2048.jpg)
![• Declaration of an array
Examples
int numbers[ ];
float averageScores[ ];
int [ ] rollNo;
float [ ] marks;
• Memory allocation for an array
Examples
numbers = new int [5];
averageScores = new float [20];
rollNo = new int [49];
marks = new float [54];
• Initialization of an array
Examples
int numbers[] = {5, 4, 2, 1, 3};
float marks[] = {2.5, 3.4, 4.5};
What is the size of the array marks?
n = marks.length;
How to define a two dimensional array?
Array in Java: A quick visit](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-76-2048.jpg)
![Declare and Allocate
Example:
int myArray [ ] [ ];
myArray = new int [3] [4];
OR
int myArray [ ] [ ] = new int [3] [4];
Creating a 2D array](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-77-2048.jpg)
![Initializing a 2D array : An example
int myArray [2] [3] = {1, 2, 3, 4, 5, 6};
OR
int myArray [ ] [ ] = { {1, 2, 3}, {4, 5, 6} };
1
6
5
4
3
2
Loading a 2D array](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-78-2048.jpg)
![ Creating a variable-sized 2D array
<type><2DarrayName>[][] = new <type> [<rowSize>][];
for (int i = 0; i < <rowSize>; i++)
<2DarrayName>[i] = new <type> [<colSizei>];
x[0]
x[1]
x[2]
Variable sized 2D array
Another way: Example
int x [ ] [ ] = new int [3][ ];
x[0] = new int [2];
x[1] = new int [4];
x[2] = new int [3];](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-79-2048.jpg)
![3D arrays : An example
class a3DArray {
public static void main(String args[]) {
int my3DArray [ ][ ][ ] = new int [3][4][5];
int i, j, k;
for(i=0; i<3; i++)
for(j=0; j<4; j++)
for(k=0; k<5; k++)
my3DArray[i][j][k] = i * j * k;
for(i=0; i<3; i++) {
for(j=0; j<4; j++) {
for(k=0; k<5; k++)
System.out.print(my3DArray[i][j][k] + " ");
System.out.println();
}
System.out.println();
}
}
}](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-80-2048.jpg)
![Example program using an array
class TestArray{
public static void main(String args[]){
int a[] = new int[5]; //Declaration and instantiation
a = {10, 20, 30, 40, 50}; //Initialization
//Traversing array
for(int i=0;i<a.length;i++){ //length is the property of array
System.out.println(a[i]);
}
// Average calculation
float sum = 0; avg;
for(i=0;i<a.length;i++) //Calculating the sum of the numbers
sum += a[i];
avg = sum/a.length;
System.out.println(“Avergae = “ + avg);
}
}](https://crownmelresort.com/image.slidesharecdn.com/chapter1-251103180612-1088d638/75/Chapter1-Object-Oriented-Programming-And-Java-pdf-81-2048.jpg)
![ANPARA THERMAL POWER STATION[1] sangam.pdf](https://cdn.slidesharecdn.com/ss_thumbnails/anparathermalpowerstation1sangam-251121115219-9261cde4-thumbnail.jpg?width=640&height=640&fit=bounds)
Chapter1 Object Oriented Programming And Java.pdf
- 1. OBJECT ORIENTED PROGRAMMINGWITH JAVA Concept of Java Programming Debasis Samanta Department of Computer Science & Engineering Indian Institute of Technology Kharagpur
- 2. Additional resources Books TheComplete Reference Java 2 (10th Edition) Hebert Schildt, Tata Mc Graw Hill Object-Oriented Programming with C++ and Java Debasis Samanta, Prentice Hall of India Website https://cse.iitkgp.ac.in/~dsamanta/java/index.htm
- 3. Concept of JavaProgramming
- 4. History of Java •James Gosling, Mike Sheridan, and Patrick Naughton initiated the Java language project in June 1991. The small team of Sun engineers called Green Team. • Firstly, it was called "Greentalk" by James Gosling, and file extension was .gt. • Java was originally designed for small, embedded systems in electronic appliances like set-top boxes, but it was too advanced technology for the digital cable television industry at the time. • After that, it was called Oak and was developed as a part of the Green project. Java team members initiated this project to develop a language for digital devices. • Later, Java technology was incorporated by Netscape as it was suited for networking.
- 5. Why Java isnamed Java? • Java was called Oak as it is a symbol of strength and chosen as a national tree of many countries like U.S.A., France, Germany, Romania, etc. • The team wanted something that reflected the essence of the technology: revolutionary, dynamic, lively, cool, unique, and easy to spell and fun to say. • In 1995, Oak was renamed as Java • Java is an island of Indonesia where first coffee was produced (called java coffee). • In 1995, Time magazine called Java one of the Ten Best Products of 1995. • JDK (Java Development Kit) 1.0 released in January 23, 1996.
- 6. The Java programmingis claimed as Java ! Java Simple Secure Portable High Performance Multithreaded Interpreted Platform Independent Dynamic Architecture Neutral Object- Oriented Robust
- 7. Current popularity Language Score Javahas worldwide popularity Parallel and Distributed development Base for Android mobile platform Reliability, speed and performanc e Java offers backward compatibility Platform Independence Java has consistently been more popular than any other programming language.
- 8. How is JavaUnique?
- 9. Von Neumann architectureof computing
- 10. Programming languages DEBASIS SAMANTA CSE IITKHARAGPUR Program 11010111 10100101 ADD X Y MOV Z A … #include<…> main(){ printf(“…”) } Assembler Interpreter Compiler Machine Level Assembly Level High Level
- 11. Third generation programminglanguages • A third generation (programming) language (3GL) is a grouping of programming languages that introduced significant enhancements to second generation languages, primarily intended to make the programming language more programmer-friendly. • English words are used to denote variables, programming structures and commands, and Structured Programming is supported by most 3GLs. • Commonly known 3GLs are FORTRAN, BASIC, Pascal, JAVA and the C-family (C, C+, C++, C#, Objective-C) of languages. Also known as a high-level programming language.
- 12.
- 13.
- 14.
- 15. FOP versus OOP FunctionOriented Programming (FOP) Object Oriented Programming (OOP) Program organization Program is divided into small parts called functions. Program is divided into parts called objects. Importance Importance is not given to data but to functions Importance is given to the data rather than procedures Approach FOP follows top down approach OOP follows bottom up approach Access Specifiers Does not have any access specifier Has three access specifiers, namely Public, Private, Protected Data Moving Data can move freely from function to function in the system Objects can move and communicate with each other Maintainability To add new data and function is not so easy Provides an easy way to add new data and function Data Access Function uses global data for sharing that can be accessed freely from function to function in the system. Object uses local data and can be accessed in a control manner Data Hiding No data hiding is possible, hence security is not possible Provides data hiding, hence secured programming is possible Overloading Polymorphism is not possible Polymorphism is possible Examples C, Visual Basic, FORTRAN, Pascal. C++, JAVA, VB.NET, C#.NET.
- 16.
- 17. Java programming paradigms Javais based on the concept of object-oriented programming. As the name suggests, at the center of it all is an object. Objects contain both data and the functionality that operates on that data. This is controlled by the following four paradigms • Encapsulation • Inheritance • Information hiding • Polymorphism
- 18. Encapsulation in Java Encapsulationin Java is a process of wrapping code and data together into a single unit, for example, a capsule which is mixed of several medicines.
- 19. Encapsulation: Example Book Borrower Title Author AccessionNo. Cost Borrower DOI Issue() Fine() Return() Open() Close() data methods Name Roll No. Address Marks Books[] Search Books() Request() Renew() Enroll() Exit() data methods
- 20.
- 21. Inheritance in Java Inheritancein Java is a mechanism in which one object acquires all the properties and behaviors of a parent object. It is an important part of OOPs (Object-Oriented Programming system).
- 22. Inheritance: Example Title Author Accession No. Cost BorrowerDOI Issue() Fine() Return() Open() Close() Book Text Reference DOP Version Department Add() Remove() Publisher Rack No. Permission Copy Type Display() Close() Open() Copy()
- 23.
- 24. Polymorphism Image Document print() In object-orientedprogramming, polymorphism refers to a programming language's ability to process objects depending on their class.
- 25. Polymorphism: Example Add(x, y): 12 +34 Add(s1 + s2) : Debasis + Samanta Add(Img, Doc) : Image + Document Add(Doc1, Doc2) : Document1 + Document2 Add two numbers Merge two strings Paste an Image to a document Merge two documents x, y; s1, s2; Img,Doc,Doc1,Doc2 Add(x, y) Add(s1, s2) Add(Img, Doc) Add(Doc1, Doc2) print()
- 26.
- 27. Features of Javaprogramming I/O Handler Java bean Packages Interfaces Exception handling Multithreading Windows toolkit Java multimedia Java swing Networking Java script JSP JDBC Distributed programming Java Core Java Applet Java Internet
- 28. Questions to think… •Can a software be developed in Java so that it runs in any OS? Any machine? • How a browser (e.g., Mozilla, Google Chrome, Safari, etc.) works in your mobile/ Computer?
- 30. OBJECT ORIENTED PROGRAMMINGWITH JAVA Java Programming Steps Debasis Samanta Department of Computer Science & Engineering Indian Institute of Technology Kharagpur
- 31. Your First JavaProgram
- 32. Program in Cand Java #include <stdio.h> int main() { printf("Hello, World!"); return 0; } import java.lang.*; class HelloWorldApp { public static void main(String args[]){ System.out.println("Hello, World!"); } } A program in C to display message A program in Java to display message Note: Both the languages are case sensitive
- 33. C versus Java AspectsC Java Paradigms Procedural Object-oriented Platform Dependency Dependent Independent Datatypes : union, structure Supported Not supported Pre-processor directives Supported (#include, #define) Not supported Header files Supported Use packages (import) Storage class Supported Not supported Aspects C Java Inheritance No inheritance Supported (Simple inheritance) Pointers Supported No Pointers Code translation Compiled Interpreted Multi-threading and Interfaces Not supported Supported Exception Handling No exception handling Supported Database Connectivity Not supported Supported
- 34. Java program editing •Any text editor can be used to write Java programs. For example, – In Windows • Notepad, Edit, Wordpad, MS-Word, etc. – In Unix • vi, emacs, gedit etc. • Save the program – Save the program in a file with the name HelloWorldApp.java
- 35.
- 36.
- 37.
- 38.
- 39. Java program compilation TheJava compiler ( javac ) converts a Java program into Java byte code – Open a DOS shell (in Windows) or Terminal (in Unix) – Move to the directory where your Java program has been saved – Enter the following command to compile: javac HelloWorldApp.java
- 40.
- 41.
- 42. Java program execution Toexecute the Java program, type the command java (from the command prompt). – For example, the current program HelloWorldApp.class can be executed as java HelloWorldApp
- 43.
- 44.
- 45. C/C++ versus Javaexecution C JAVA
- 46.
- 47. C++ versus Java Areasof applications – C++ is best suitable for developing large software. • Library management system, Employee management system, Passenger reservation system, etc. – Java is best suitable for developing communication/ Internet application software. • Network protocols, Internet programs, web page, web browser, etc.
- 48. C++ versus Java: Programming features Features in C++ in Java Data abstraction and encapsulation √ √ Polymorphism √ √ Binding Static √ √ Dynamic √ √ Inheritance Single Inheritance √ √ Multiple Inheritance √ × Operator overloading √ × Template classes √ × Global variables √ × Header files √ × Pointers √ × Interface and packages × √ API (Application Programming Interface) × √
- 49. C++ versus Java: Programming environments C++ source code C++ Complier C++ object code Java source code Java BYTE code Java compiler Java interprter WIN32 Java interprter Solaris Java interprter Macintosh Intel Pentium Sun Solaris Apple Macintosh JVM C++ provides platform dependent programming Java provides platform independent programming
- 50. Questions to think… •How a Java program can include two or more classes and then compile them? • How a browser can run a Java program?
- 52. OBJECT ORIENTED PROGRAMMINGWITH JAVA Java Tools and Resources Debasis Samanta Department of Computer Science & Engineering Indian Institute of Technology Kharagpur
- 53.
- 54. Tools available forJava programming • Java Software Developer’s Kit (SDK) : JavaTM 2 SDK – SDK from JavaSoft, a division of Sun Microsystems Inc. – Contains the basic tools and libraries necessary for creating, testing, documenting and executing Java programs. • JavaTM 2 SDK, Standard Edition https://java.sun.com/j2se/1.4.2/docs/index.html – Official site for JavaTM 2 SDK, Standard Edition
- 55. Tools available forJava programming There are seven main programs in SDK javac – the Java Compiler java – the Java Interpreter javadoc – generates documentation in HTML appletviewer – the Java Interpreter to execute Java applets jdb – the Java Debugger to find and fix bugs in Java programs javap – the Java Disassembler to displays the accessible functions and data in a compiled class; it also displays the meaning of byte codes javah – to create interface between Java and C routines
- 56. Tools available forJava programming • Additional few sources Javatpoint website : Another official site for JavaTM 2 SDK, Standard Edition, help, tutorial, etc. https://www.javatpoint.com/java-tutorial Free Java Download : Download Java for your desktop computer now https://www.java.com/en/download/index.jsp
- 57. Resource for Javaprogramming • There are many resources for learning Java The JavaTM2 Tutorials • The Java tutorials are practical guides for programmers who want to use the Java programming language to create applications. https://java.sun.com/docs/books/tutorial/index.html Sun Developer Network • Sun Microsystem's official website listing down all the API documentation, latest Java Technologies, books and other resources. https://java.sun.com/reference/docs/
- 58. Packages in Java API(Application Programming Interface) in Java SDK – The API enables Java programmers to develop varieties of applets and applications – It contains nine packages • java.applet – for applet programming • java.awt – the Abstract Windowing Toolkit for designing GUI like Button, Checkbox, Choice, Menu, Pannel, etc. • java.io – file input/output handling • java.lang – provides useful classes like to handle Object, Thread, Exception, String, System, Math, Float, Integer, etc.
- 59. Packages in Java •java.lang – provides useful classes like to handle Object, Thread, Exception, String, System, Math, Float, Integer etc. • java.net – classes for network programming; supports TCP/IP networking protocols • java.util – it contains miscellaneous classes like Vector, Stack, List, Date, Dictionary, Hash etc. • javax.swing – for designing graphical user interface (GUI) • java.sql – for database connectivity (JDBC)
- 60. Other third parttools for Java programming Java IDE (Integrated Development Environment) – Number of IDEs are available to support the productivity of software development • Sun’s Java Workshop from Sun’s JavaSoft (recently powered with Visual Java) • Mojo from Penumbra Software (best visual environment for creating Java applets) • Jumba from Aimtech and IBM (graphical applet builder) • Semantic Café from Semantics (a de-facto standard for Java development on Windows systems)
- 61. Other third parttools for Java programming Web browser – Java environment requires Java-enabled web browser to supports Java applets – Few (free) popular Java-enabled web browsers: • HotJava from JavaSoft web site (http://java.sun.com) • Netscape Navigator from Netscape home page (http://home.nescape.com) • Internet Explorer from Microsoft’s web page (http://www.microsoft.com)
- 62. Few more fromJava professionals Net Beans - https://netbeans.org/downloads/ − This is one of the most commonly used IDEs for Java and some major languages. NotePad++ - https://notepad-plus-plus.org/download/v7.5.8.html − This is a very advanced and handy NotePad, it has several built-in tools and functions for making programming easy.
- 63.
- 64. A rich subsetof the Java language
- 65. Built-in data typesin Java Type Size boolean 1 bit byte 8 bits char 16 bits short 16 bits Type Size int 32 bits long 64 bits float 32 bits double 64 bits In Java, every variable has a type declared in the source code. There are two kinds of types: reference types and primitive types. Reference types are references to objects. Primitive types directly contain values.
- 66. The Java characterset •The Java language alphabet •Uppercase letters ‘A’ to ‘Z’ •Lowercase letters ‘a’ to ‘z’ •Digits ‘0’ to ‘9’ •Java special characters: , < > . _ ( ) ; $ : % [ ] # ? ' & { } " ^ ! * / | - ~ +
- 67. Identifiers in Java •Identifiers • Names given to various program elements (variables, constants, class, methods, etc.) • May consist of letters, digits and the underscore (‘_’) character, with no space between. • Blank and comma are not allowed. • First character must be an alphabet or underscore. • An identifier can be arbitrary long. • Identifier should not be a reserved word. • Java programming language is case sensitive. • area, AREA and Area are all different!
- 68. Datatype declaration rule Declarationand assignment statements int a, b = 0; a = 123; b = 45; int c = a + b; System.out.print(“The sum is” + c);
- 69.
- 70. Following are thethree tasks to manipulate an array in Java • Declaration of an array. • Allocate memory for it. • Loading the values into array. An array is a finite, ordered and collection of homogeneous data elements. 0 1 2 3 4 n-1 n-2 marks marks.length = n Array in Java
- 71. Declaration of array <type><arrayName>[ ]; Example: int x[ ]; <type>[ ] <arrayName>; Example: int [ ] x; Creating an array Allocate memory for an array <arrayName> = new <type> [<size>]; Example: x = new int [100 ];
- 72. Define and allocatememory together <type> <arrayName> [ ] = new <type> [<size>]; Example: int x [ ] = new int [100]; Creating an array
- 73. Initialization of Array <arrayName>[<subscript> ] = <value>; Example: x [5] = 100; for (int i = 0; i < 100; i++) x[i] = <value>; Storing elements in array
- 74. Initialization of array:An alternative way <type> <arrayName> [ ] = { <list of values> }; Example: int x [ ] = {12, 3, 9, 15}; Storing elements in array Here, declaration, allocation of memory and array initialization all are at one go!
- 75. • Insertion • Insertionat any location • Insertion at front • Insertion at end • Insertion is sorted order • Deletion • Deletion a particular element • Deletion an element at a particular location • Deletion the element at front • Deletion the element at end • Searching and Traversal • Finding the smallest and largest element • Printing all element or some specific element • Sorting • In ascending order, descending order, lexicographical order etc. Processing elements in an array
- 76. • Declaration ofan array Examples int numbers[ ]; float averageScores[ ]; int [ ] rollNo; float [ ] marks; • Memory allocation for an array Examples numbers = new int [5]; averageScores = new float [20]; rollNo = new int [49]; marks = new float [54]; • Initialization of an array Examples int numbers[] = {5, 4, 2, 1, 3}; float marks[] = {2.5, 3.4, 4.5}; What is the size of the array marks? n = marks.length; How to define a two dimensional array? Array in Java: A quick visit
- 77. Declare and Allocate Example: intmyArray [ ] [ ]; myArray = new int [3] [4]; OR int myArray [ ] [ ] = new int [3] [4]; Creating a 2D array
- 78. Initializing a 2Darray : An example int myArray [2] [3] = {1, 2, 3, 4, 5, 6}; OR int myArray [ ] [ ] = { {1, 2, 3}, {4, 5, 6} }; 1 6 5 4 3 2 Loading a 2D array
- 79. Creating avariable-sized 2D array <type><2DarrayName>[][] = new <type> [<rowSize>][]; for (int i = 0; i < <rowSize>; i++) <2DarrayName>[i] = new <type> [<colSizei>]; x[0] x[1] x[2] Variable sized 2D array Another way: Example int x [ ] [ ] = new int [3][ ]; x[0] = new int [2]; x[1] = new int [4]; x[2] = new int [3];
- 80. 3D arrays :An example class a3DArray { public static void main(String args[]) { int my3DArray [ ][ ][ ] = new int [3][4][5]; int i, j, k; for(i=0; i<3; i++) for(j=0; j<4; j++) for(k=0; k<5; k++) my3DArray[i][j][k] = i * j * k; for(i=0; i<3; i++) { for(j=0; j<4; j++) { for(k=0; k<5; k++) System.out.print(my3DArray[i][j][k] + " "); System.out.println(); } System.out.println(); } } }
- 81. Example program usingan array class TestArray{ public static void main(String args[]){ int a[] = new int[5]; //Declaration and instantiation a = {10, 20, 30, 40, 50}; //Initialization //Traversing array for(int i=0;i<a.length;i++){ //length is the property of array System.out.println(a[i]); } // Average calculation float sum = 0; avg; for(i=0;i<a.length;i++) //Calculating the sum of the numbers sum += a[i]; avg = sum/a.length; System.out.println(“Avergae = “ + avg); } }
- 82. Questions to think… •How to write recursive programs in Java? • Which program? Application or applet?