Features Of Java

                            

History of java:-
In 1990,Sun Microsystems Inc.(US) has conceived a project to develop software for consumer electronic devices that could be controlled by remote.
        In 1991 Bill Joy,James Gosling,Mike sheradin and seveal others met and discuss about this project.Finally they developed new Language in 1993 called Oak.But this name was registered by some other company.Later it was changed to Java.
In 1994,They developed a web browser called "HotJava".It is the first web-browser,having the capabilities of executing applets,which are programs designed to run dynamically on Internet.
In 1995, They announced Java and HotJava at Sunworld conference.After that on 1996 January 23 JDK1.0 version was released.

                         

                                    Features of Java
                                    ----------------
1.Simple:-
Java is a simple programming language.Because of 2 reasons.
1)Java Soft people maintained the same syntax of C and C++ in Java.
2)Pointers are eliminated in Java.
IIQ) Why pointers are eleminated from Java?
1)Pointers can crash program very easily.
  2)Using pointers,it is possible to develop harmful programs like virus and haking programs. So Pointers are security threat for java.
   Because of these reasons pointers are eleminated from java.

2) Object-Oriented:-
Java programs use Objects and classes.
     Object:- An object is anything that exists physically in this world.
               An object will have properties(variables) and actions(methods).
     variable:- It represents memory location to store data.
     
      Class:- It is a group name that specifies properties and actions of objects.
         ==> class also contains variables and methods.
==> Class is only specification but object exist physically.
==> Class is a model for creating Objects.

3)Distributed:-
Information is distributed on various computers on a network.
Using java,we can write programs which capture information and distribute it to the clients.

4)Robust:-
Robust means strong.Java programs are strong and they don't crash easily like c and C++.
There are 2 reasons for this.
1)Java has got excelent exception handling features.
2)Memory management features.
    Here memory allocation is done by JVM's Class loader subsystem.
    Memory deallocation is done by JVM's garbage collector.

5)Secure:-
Security problems are eleminated by using java on Internet.

6)System Independence:- (or) Architecture neutral
  Java's byte code is not machine dependent.It can be run on any machine with any processor.

7)portable:-
If a program yeilds the same result on every machine,then that program is called portable.This is the result of java's system independence nature.

8)Interpreted:-
        In any other language,only one interpreter or compiler is used to execute the program.But in java,we use both compiler and interpreter for the execution.

9)Multi-threaded:-
Executing statements are called thread.Each thread can excute no of statements.This is essential feature to server side programs.

10)High performance:-
The problem with interpreter inside the jvm is that it is  slow.Because of this,Java programs used to run slow.To overcome this problem,along with the interpreter javasoft people introduced JIT(Just In Time)compiler,which enhances the speed of execution.