Java 7, Java 8 and Java 9
A high-level programming language developed in 1995 by Sun Microsystems is Java. Java is supported by a wide variety of platforms such as the Mac operating system, Windows operating system, different versions of Unix, etc. The source code in a java programming language is written in text files and the text files end with the .java extension.
Then the javac compiler compiles the source files into .class files. The .class files contain codes in bytecodes. The machine language of java virtual machine is bytecodes. The application is then run by the java launcher with an instance of a java virtual machine. Java is a simple language, object-oriented and dynamic.
The main reasons to learn java are:
1. Object-Oriented: Java is based on an object model and it can be easily extended. Everything is an object in Java.
2. Platform independent: When the source code is compiled by the java compiler, the compilation is not done into a platform-specific machine-like in other programming languages such as C, C++, etc. But it is compiled into bytecodes which is independent of the platform. Regardless of the platform java is being run on, the bytecode is interpreted by the Java Virtual Machine (JVM) after it is distributed over the web.
3. It is a simple language: Java programming language is designed in such a way that it is easy to learn.
4. Java is secure: Java programming language has a security feature through which tamper-free, virus-free systems are developed.
5. Java has a neutral architecture: The object file format generated by the java compiler is architecture-neutral because of which the compiled code can be executed on many processors.
6. Java is portable: Because java is architecture-neutral and the specification does not contain aspects that are implementation-dependent making java portable.
7. Java is robust: The compile-time errors and run-time errors are checked by java to eliminate error-prone situations.
The applications of Java are:
1. Java is the multithreaded programming language: Programs can be written to perform the tasks simultaneously using a multithreaded feature in java. The developers use a multithreaded feature of java to construct interactive applications.
2. Java is interpreted language: The bytecode in java is not stored anywhere and it is translated into machine instructions. The linking is a lightweight and incremental process; hence the development process is faster and analytical.
3. Java provides high performance: Java provides high performance because of the use of just in time compilers.
4. Java is distributed: The internet’s distributed environment is supported by java.
5. Java is dynamic: Java adapts to any environment even if it's evolving. Hence it is dynamic when compared to other programming languages like C, C++, etc.
Java program to print “This is a java program”
public class program
public static void main(string args)
System.out.println(“This is a java program”)
There are no prerequisites as such to learn java but a good understanding of computer programs and programming languages is necessary.
Beginners can refer to this tutorial to understand the basics of Java. This tutorial is helpful for people who want to pursue a career in the field of Java. This tutorial is good learning for all other readers.