Tprograming: JAVA - Introduction

Java is a class-based , simple , object oriented programming language .It is general purpose programming language used to develop applications can independent of any platform and can write and run anywhere .

It works on many platforms like windows , Linux , Mac , Raspberry pi , etc.

History of java :

Java is a world-wide used programming language . Initially java was developed by scientists James Gosling by Sun Microsystems in 1995 .

Later java was handover to Oracle and now java has been handled by Oracle .

Applications of java :

Mobile Applications
Desktop applications
Web servers
Application servers
Games
Database

Features Of JAVA :-

1. Class : Class is a special block of code which is executed using object .Class has its data members and member functions . Class keyword is used to declare a class .

2. Object : Object is a instance of class . It is an sub part of class .

In the above example , there are given laptop with brands

Laptop is a main block i.e. class and its brands are its different objects It means object is an instance of class .

Object has two properties state and behaviour

3. Data Abstraction : Data abstraction points to useful and essential information or data . The visibility of useful data and hiding un-useful data is called as data abstraction .
For example , we sends messages on email , watsapp , etc . We can able to see only message not process behind it .

4. Polymorphism : The meaning of poly is many and meaning of morphism is forms .It is an ability to take more than many forms . We can create many forms of one thing this process is called as polymorphism .

5. Message Passing : It means the communication between objects , data or classes .

6. Encapsulations : The providing security to data like wrapper class called as encapsulation .
For example , medicine capsule is one type of wrapper , it consists of small small particles that means it provides security to those small particles inside it .

7. Inheritance : The child class or derived class derives/inherits properties from parent class or base class is called as inheritance .
For example , We takes some features from our parents like color body features etc , this property is called as inheritance .

8. Data binding : The holding of data together is called as data binding .

Data types in java :

Data types are used in every programming language .It is an essential part of any program .
Data types are used to show which type of data you are using in a program .

There are two types of data types in java :

Note : Everything in java is an string , which means if you have to store integers or floats so you have to convert in these data types .

1.Primitive data types :

Data types which are pre-defined by an system called as primitive data types .
i) int :

int data type is an 32-bit signed integer .
The numbers or integers are of int data type
It has rang of -2,147,483,648... to 2,147,483,847
The default value is 0
Example : int t=2000

ii) char :

char is an single 16-bit unicode character
Alphabets , letters are of char data type
Minimum value is '\u0000'(or 0)
Maximum value is '\uffff'(or 65,535)
Exanple : char t='tprograming

iii) float :

Float is an single-precision 32-bit IEEE 754 floating point
single decimal points are stored here
Minimum value is 0.0f
Example : float t=4.3

iv) double :

It is an double-pricision 64-bit IEEE 754 floating point
Is is used to store long decimal points
Default value is 0.0d
Example : double t=2345.098

v) byte :

Byte is an 8-bit signed integer
It has range from -128 to 127
Default value is 0
Byte is four times smaller than int
Example : byte t=100

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JAVA - Introduction