Core Java Part-1

1. Object Oriented
Technology
The
JAVA
Language
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2. Programming Languages
•To adapt to
changing environments and
uses
•To implement
refinements and improvements
in the art of programming
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3. History of OOPs

In 1960s Birth of Structured
Programming Language
 In early 1980s object-oriented
programming (OOP)
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4. History of OOPs
 In
1979 C++ invented by
Bjarne Stroustrup
1980s and the early 1990s,
C++ took hold.
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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)
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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
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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.
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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
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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
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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.
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11. Java Buzzwords
 Simple
 Secure
 Portable
 Architecture
Neutral
 Interpreted
 High
 Object-oriented performance
 Distributed
 Robust
 Multithreaded  Dynamic
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12. Java Versions
 Java 1.0
 Java 1.1
 Java 2, ver.1.4
 Java 2, ver.1.5
 Java 2, ver.1.6
 Java 2
 Java 2, ver.1.2
 Java 2, ver.1.3
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13. Java the OOP Language
 The Three OOP Principles
• Encapsulation
• Inheritance
• Polymorphism
 Abstraction
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14. Encapsulation
A
getA( )
B
getB( )
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15. Inheritance
Bird
Flying
Robin
Non-Flying
Swallow
Penguin
Kiwi
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16. Polymorphism
Shape
Draw( )
Draw( a, b )
Draw( a )
Draw( a, b, c )
Rectangle
Circle
Triangle
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17. • Run
time entity
Object
• Represent a
Person, Book,
Bank Account, etc…
• User defined data
Object : Student
DATA:
Roll_no
Name
Percentage
FUNCTIONS:
Total
Average
Display
• Example:
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18. • Set
Class
of Data & Code is
class
•User defined data-type
• Example:
 Fruit,
 Furniture
CLASS
DATA:
:::::::::::::
:::::::::::::
FUNCTIONS:
::::::::::::
::::::::::::
 Vehicle
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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
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20. Data Types
• Java supports eight different basic data types.
Type
Size in
Character
Boolean
Byte
Short
Integer
Long
Float
Double
Bytes
2
1 bit
1
2
4
8
4
8
Description
Keyword
16 bit Unicode
char
1 – bit
boolean
8 – bits
byte
16 – bits
short
32 – bits
int
64 – bits
long
32 – bits
float
64 – bits
double
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21. Declaration & Initialization of
variable
Datatype varName; // Declaration of Variable
varName = Value;
Example:
int count = 22;
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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;
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23. Declaration & Initialization of
variable
long m = 254836L;
System.out.println(“The value of m is “ + m);
Output:
The value of m is 254936
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24. Declaration & Initialization of
variable
Character & Strings
char ch = ‘A’;
String s1= “This is Testing”;
//String is a class provide by Java.
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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);
}
Jainul A. Musani
}
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