What is Java
But now, almost everything can be done by smartphone and the internet. And this has been made possible due to the high-level programming language, Java.
So friends, in this tutorial, let us know complete information about the class-based, object-oriented programming language, what is Java.
JAVA is an object-oriented programming language. And Java is a widely-used programming language. which is explicitly designed for use in the distributed environment of the Internet.
Java is the fastest, most reliable, and safest way to write any programming language or run programs. And Java language is used for desktop and mobile applications etc.
Oracle Corporation is the current owner of Java, and according to it, Java runs on 3 billion devices worldwide.
So let's know the history of Java in brief.
History of Java (History of Java):
Friends, in June 1991, the Java language was started by James Gosling under the name “ Oak ”. Which was later renamed Java in 1995.
And the Java programming language has been developed jointly by James Gosling and his team members Mike Sheridan, and Patrick Naughton.
The Java language was developed in 1995 for digital devices such as televisions, set-top boxes, etc.
That is, the first public implementation of java was Java v1.0 in 1995. And right now the latest version of Java is " Java 13 (SDK 13)".
Friends, this was the history of Java, in brief, I hope that now you must have understood what is Java and its history. So now let's come to its components.
Components of Java
Friends, there are mainly three components of the Java programming language :
1. JDK: Its full form is Java Development Kit. And it provides the environment to develop Java programs and execute the code.
And JDK is used only by Java Developers.
2. JVM: Its full form is Java Virtual Machine. It is an abstract machine and through this, the Java program is run.
That is, it enables the Virtual Machine to run Java code on your computer.
3. JRE: Java Runtime Environment is a software package that provides class libraries, Java Virtual Machine (JVM) to programs written in Java language.
That is, it is only used to run Java programs.
Friends, Java has three main components. Let us know about some important features of Java.
Features of Java
Well the Java language has a lot of features, here are some of the important features below:
#1. Simple and Familiar:
Friends, the code written in the Java programming language is very easy to read, write and learn. And Java is similar to C / C++ language.
Learning Java will be very easy if you learn the C/C++ programming language first.
Because C/C++ complexities like pointers and multiple inheritances have been removed.
To learn about J language: Go to " C language in Hindi ".
#2. Java Supports Functional Programming:
The functional interfaces and Lambda Expressions feature have been updated in Java SE version 8 (JDK 8) to increase the flexibility of the Java language.
#3. Java is Secure:
The Java language has compile-time and runtime checking (security manager) for security features. Which is done through static type-checking.
And keeps your application safe from attack from outside.
#4. High Performance:
Java code is compiled from bytecode, which is highly optimized. That is why the Java Virtual Machine (JVM) is able to execute any Java application at full speed.
Types of Java Application
Friends, if you are thinking of making applications using Java programming, then there are mainly four types of Java applications you can create:
#1. Mobile Applications: Java ME is a cross-platform developed to run mobile applications on smartphones.
That is, Java is a platform for Android App Development.
#2. Standalone Applications: Java standalone applications that use GUIs, such as AWT, Swing, and JavaFX. That is, there are buttons, a list, a menu, and scroll panel.
#3. Web Applications: The applications which run on the server are called web applications.
And a web browser is used to access the web application.
#4. Enterprise Applications: The applications which are distributed in nature are called Enterprise Applications.
- Mainly you can create these 4 types of applications with java language.
What is Java Machine Code and Bytecode:
Machine code is a computer program, which is written in machine language. That is, the java source code is designed to run in the Java Virtual Machine (JVM).
Java Bytecode is a program code, which compiles the machine code. That is, to run the software code in the Java Virtual Machine (JVM), the machine code is first compiled, and then the Java bytecode program is executed.
How Java Works
Programs in JAVA are not compiled into executable files. Java code is compiled into intermediate binary ie JVM (Java Virtual Machine) byte code.
And then interpret the byte code to run the program. The Java source code is converted into bytecode compiled by the javac compiler into machine code.
That is, the Java program is compiled twice to be executed:
- First of all, Java code is compiled into bytecode.
- As soon as the bytecode is run, it has to be converted into machine code.
Why is Java Important - Why Is Java Important?
Friends, Java language is one of the most popular programming languages, with this you can easily create web and mobile applications.
Java is the best in terms of flexibility, speed, and security. Here some important points have been mentioned below:
- Java is a high-level language, which is very easy to learn.
- Platform independent means that Java programs can be run on any machine.
- Java एक object-oriented programming language है।
- It also has a garbage collector, which means you can prevent memory leaks. And helps in detecting unused data.
Friends, Java is a demanding programming language, if you want to become a web or Android developer, then you must learn Java.
To know about Android OS, go to " Android Operating System " here.
Let us now see the sample of how to make the first java program :
Java Hello World Program
The easiest program of Java program is to print "Hello World" on the screen and then know about all the codes:
class HelloWorld { public static void main(String[] args) { System.out.println("Hello World!"); } }
If you want to run this code by copying it, then save it with the file name HelloWorld.java.Output: Hello World!Note: The class name you keep in the Java program will have to be the same file name.
