Skip to content

Latest commit

 

History

History
102 lines (71 loc) · 3.37 KB

About Java.md

File metadata and controls

102 lines (71 loc) · 3.37 KB

Table of Content

About Java
Java character set
History of Java
Features of Java

About JAVA☕

  • Father: James Arthur Gosling aka Dr. Java (1955)

  • Principle: Simple, Robust, Portable, Platform-independent, Secured, High Performance, Multi-threaded, Architecture Neutral, Object-oriented, Interpreted, and Dynamic

  • Etymology: Java is an island of Indonesia where first coffee was produced(Java Coffee)

  • Paradigm: Generic, Object-oriented, Imperative, Reflective

Java character set

Java uses Unicode character set.
65,536 characters are available in Java
For Example:

  • A: 65 (ASCII for A)
  • B: 66 (ASCII for B)
  • A(devanagari): 400 (ASCII)
  • Aa(devanagari): 401 (ASCII)

History of Java

  • Java is one of the programming language created for development of distributed applications
  • Java software is developed at SunMicro Systems by James Arthur Gosling
  • Java development was started in the year 1990 and completed in the middle of 1991
  • Guardians of Java
    • SunMicro System has handed over entire rights of Java to Oracle

NOTE

  • Java software is available in the form of JDK (Java Development Kit)

  • In the real industry, Java software is present in 3 categories

    • J2SE (Java to Standard Edition) 
      •  used for developing client side applications
    • J2EE (Java to Enterprise Edition) 
      •  used for developing server side applications
    • J2ME (Java to Micro Edition) 
      •  used for developing mobile applications

Features of Java

Simple

  • Java is simple language and the basic reason behind this is that Java has removed the concept of pointers
  • Pointers lead to confuse program
  • Pointer may crash program easily
  • Pointers may break security

Object Oriented

Java is object oriented which supports features of object oriented language:

  • Features of OOPS
    • class
    • object
    • encapsulation
    • abstraction
    • inheritance
    • polymorphism

Robust

  • Robust means strong; Java programs do not crash easily
  • There are two reasons behind it:
  • Java has powerful concept called Exception handling (run time problems)
  • Java has in-built memory feature
  • Most of the C/C++ programs crash in the middle because they are not able to allocate sufficient memory or forget to free the allocated memory.
  • Such problems are not present in Java because here user need not to allocate/reallocate the memory. Every care would be taken by JVM(Java Virtual Machine)

Architecture Neutral

  • Java is Architecture Neutral Language because the size of data type is same across the platform

Portable

  • Portable applications are those which can run on each and every Operating System; and each and every processor without considering their vendor.

Platform Independent

  • Java is a Platform Independent Language
  • .java is converted to .class file after being compiled.
  • This .class file is then converted to native code of OS
  • Note: JVM is Platform Dependent

Multi-Threaded

  • Thread is a light-weight process.
  • The basic aim of multi-threading is to achieve concurrent execution
  • The flow of control in Java is known as Thread
  • The purpose of thread is to execute the program

Secure

  • Java program has pre-defined API for security