1 The JAVA Language Object Oriented Technology Mithani Binjan M

2 Programming Languages To adapt to changing environments and uses To implement refinements and improvements in the art of programming

3 History of OOPs  In 1960s Birth of Structured Programming Language  In early 1980s object-oriented programming (OOP)

4 History of OOPs  In 1979 C++ invented by Bjarne Stroustrup  1980s and the early 1990s, C++ took hold.

5 History of OOPs  In 1991 Java was conceived By James Gosling, Patrick Naughton, Chris Warth, Ed Frank, and Mike Sheridan  At Sun Microsystems, Inc. “Oak”  “Java” ( 1995 )

6 Java the Language of Internet  Expanded the universe of objects  Objects can move about freely in cyberspace.  On a network :  passive information/data  dynamic, active programs

7 Java Applications -&- Java Applets  An application is a program that runs on your computer, under the operating system of that computer.  An applet is an application designed to be transmitted over the Internet and executed by a Java-compatible Web browser.

8 Java’s Magic: The Bytecode  An application a highly optimized set of instructions designed to be executed by the Java run-time system - JVM  JVM - Java Virtual Machine  Truly Portable

9 JVM  Interpreter  JVM needs to be implemented for each platform.  Platform independent  Bytecode enables the Java run-time system to execute programs much faster

10 Just In Time (JIT) compiler  Sun supplies its Just In Time (JIT) compiler for bytecode. (Java-2)  JIT compiler is part of the JVM.  It compiles bytecode into executable code in real time, on a piece-by-piece, demand basis.

11 Java Buzzwords  Simple  Secure  Portable  Object-oriented  Robust  Multithreaded  Architecture- neutral  Interpreted  High performance  Distributed  Dynamic

12 Java Versions  Java 1.0  Java 1.1  Java 2  Java 2, version 1.2  Java 2, version 1.3  Java 2, version 1.4  Java 2, version 1.5  Java 2, version 1.6

13 Java the OOP Language  The Three OOP Principles Encapsulation Inheritance Polymorphism  Abstraction

14 Encapsulation getB( ) A B getA()

15 Inheritance Bird FlyingNon-Flying RobinSwallowPenguinKiwi

16 Polymorphism Shape Draw( ) Draw( a, b )Draw( a )Draw( a, b, c ) Rectangle Circle Triangle

17 Object Run time entity Represent a PERSON, BOOK, Bank Account, etc… User defined data Example: Object : Student DATA: Roll_no Name Percentage FUNCTIONS: Total Average Display

18 Class Set of Data & Code is class User defined data-type Example: Fruit, Furniture Vehicle CLASS DATA: ::::::::::::: FUNCTIONS: ::::::::::::

19 Variables & Data Types Named memory location that holds a value In java variables must be declared before it use in the program Variable must be of some datatype, it tells compiler what type of value it can store

20 Data Types Java supports eight different basic data types. Type Size in bytes DescriptionKeyword Character216-bit Unicode char Boolean- true / false1-bitboolean Byte18-bitbyte Short216-bitshort Integer432-bitint Long864-bitlong Float432-bitfloat Double864-bitdouble

21 Declaration & Initialization of variable Datatype varName; // Declaration of Variable varName = Value; Example: int count = 22;

22 Declaration & Initialization of variable float x, y, z; // value here considers as ‘double’ type x = 10.35; x = 10.35f; y = 24.56F; z = y;

23 Declaration & Initialization of variable long m = L; System.out.println(“The value of m is “ + m); Output: The value of m is

24 Declaration & Initialization of variable Character & Strings char ch = ‘A’; String s1= “This is Testing”; //String is a class provide by Java.

25 Guess the Output Class test { public static void main(String s[]) { char c; boolean flg; int a; System.out.println(c); System.out.println(flg); System.out.println(a); }