Java Virtual Machine

Java uses both Compiler and Interpreter. Source code written in Java is compiled to generate bytecode and then this bytecode is interpreted to machine instructions for specific machine.

Java Statements


A statement is an executable combination of tokens ending with a semicolon(;). Statements are usually executed in sequence in the order in which they appear. Java implements several types of statements and these are:

Classes and Object

Main concept of object oriented language


           Classes are the basis for any object oriented system classes have well defined boundaries and describe a set of objects that share similar properties and perform similar functions. Classes can be reused within a system or they can be used while developing a new system.

Difference between Conventional and object oriented language



Before we talk about object oriented programming, we must know about all the programming like structured, procedural etc.

Java Virtual Machine

     JVM is a virtual machine that act as an interpreter between java byte code and a computer’s operating system.By using JVM we can run java code on any platform.A JVM include a JIT(just-in-time)compiler within it.JIT compiler converts whole program to bytecodes . JVM recognizes a particular format of a file called “class file(extension.class)”. Each "class file(extension .class)" contains the definition of a single class or interface.


Difference between C C++ and Java


1)Language->C is a procedural language,c++ is a object oriented language .Java is a pure object oriented language.

2)Header Files->In C we use stdio.h header file .In C++ we use iostream.h,conio.h headerfile but Java does not support any header files.

Access Modifiers in Java


Access modifier is a reserve keyword or we can say visibility controls which is used to restrict access.We can use these access modifier to determine whether a fields or methods in a class ,can be called or used by another class or sub class or not.That means these access modifiers can prevent unauthorized updation or execution of fields and methods of the particular object.


Features of Java


       In a computer language either compiler or interpreter is used. But in Java both are used .The Java compiler translates source code into bytecode. Bytecodes are not machine codes after compiles the program Java interpreter generates machine codes that can be executed or running the program that is why we can say that Java compiled and interpreted. These two steps provide security.

Introduction to Java

Java is an object oriented programming language which was developed by James Gosling at Sun Micro System in 1991 and released in 1995.The original name of Java called OAK. Java was designed for the development of electronics devices like TVs, Machines etc.