In this chapter you will learn
- How Java Works?
- Advantages of Java
- What are Java Compiler and Interpreter?
Welcome to the first chapter of core java. It is the very first chapter and from here you will start your journey. This journey is surely going to adventures and challenging where you will find a new way see the world using java programming. As, we promised to provide complete java programming for each topics and deliver less theory; it is always our mind. But before starting the journey of JAVA, do you know over 3 million devices are using java these days. Your calculators, DVD Player, Printing machine, digital watch, remote control, television etc are working because of java. So, the simple question which you are thinking why java, why not other languages? If you are thinking this question then surely you are smarter one. Answer is very interesting and you must know the structure of Java code.
How Java Works?
If you compare Java to other high level programming language, the bigger difference which you would find is platform independency. For example if you compile C++ code it will only work on windows platform. It will never work on linux machine. To work on linux machine you will have to make another version of your program.
On the other hand, Java is platform independent. If you compile your code with Java compiler it will work on windows, linux and all other platform which is Java enabled. Java compiles its code into
bytecode using JVM (Java Virtual Machine).
Bytecode is not an executable file but it is precompiled and ready to be executed using java interpreter. A java enabled machine get this bytecode and execute them with the help of interpreter.
There is 2 steps of compiling and executing Java program.
1. JVM (Java Virtual Machine) – Compile Java Program into bytecode using javac command.
2. Java Interpreter – Execute java bytecode using java command.
How to setup my PC for Java Programming?
Don’t worry if your machine is not set or configured for java programming. We assume that you have just bought your PC and no software is installed. We will start from scratch and gives you fully details of each topic with graphical as well as programmatically help. In the next chapter you will learn How to configure your PC for java programming. This chapter includes
1. Downloading and installing java
2. Setting path (windows xp, windows vista/7/8/10)
3. Checking whether java is working or not
4. Writing a demo java program and executing them.
So, what are you waiting for? Be ready for configuring your machine if you haven’t configure yet for JAVA.
In this chapter you have learned the importance of Java Programming in short. It is practical based learning so, the next entire lesson you will understand java with real time programming. Next chapter is downloading and Installing Java.