Introduction of Java

Java is a high level programming language which is used for creating various types of software's or applications.

Types of java applications:-

1)    Stand alone application

2)    Desktop based application         

3)    Web based application

4)    Enterprise application etc.

Stand alone application:-Stand alone application run on single machine without user interface and every stand alone application having main method.

Desktop based application:-Desktop based application also run on single machine with user interface and every Desktop based application having main method.

Web based application:-Web based application run on web, web based application not required main method but for such types of application need server.

Enterprise application:-Enterprise application is category of web application where doing some business or involve some money related issues.

Java Editions: - There are four Java platforms.

·         Java Platform, Standard Edition (Java SE)

·         Java Platform, Enterprise Edition (Java EE)

·         Java Platform, Micro Edition (Java ME)

·         JavaFX

Initially java was the product of sun micro system,but now a days java is a product of Oracle corporation.

java is a object oriented programming language developed by James Gosling in year 1995,initially this language was known by another name that was OAK.after that OAK is renamed as Java language.the purpose behind the java technology was platform independence that means product run on any platform(OS).

Object oriented programming having some features,object oriented means representation of real world using technology.

Features of Object Oriented programming(OOPS)

1.     class

2.     object

3.     data hiding

4.     abstraction

5.     encapsulation

6.     inheritance

7.     polymorphism

8.     constructor

9.     overloading

10. overriding

  class is a logical unit or class is a formula for creating objects.class having many definitions.

in real world class is not exist ,class is collection of objects,class is collection of data and methods(functions),here data means variables which can store values and methods are used to fill values  into variables ,getting values from variables.

how to create class:-

                                  syntax for create a class is

                                   class classname                                   class Test

                                  {                                                            {

                                                                for Example

                                  }                                                            }    

here class is keyword in java.  

in java  class may be empty,can contains only variables,can contains only methods and can contains both variables as well as methods.  

for example

class may be contains

class Student

{

//empty class

}

class may be contains

class Student

{

String name;

int rollno;

}

class may be contains

class Student

{

void set()

{

}

void disp()

{

}

}

class may be contains

class Student

{

String name;

int rollno;

void set()

{

}

void disp()

{

}

}