Java Tutorial

 

 
What is java :-

• Java is a popular programming language.

• Java is used to develop mobile apps, web apps, desktop apps, games and much more.

• Java is developed by James Gosling and released by Sun Microsystems in 1995.

• It is also owned by oracle.

 Feature of java :-

• It is platform independent language.

• It is portable java language supported.

• It is reusable.

• It is easy to learn and simple to use.

• It is open-source and free.

• It is secure, fast and powerful.

Application of java :-

• Mobile Application

• Web development

• Games

• Database Connect

• Web server

Access Modifiers :-

Access Modifier	Within Class	Within Package	Outside Package by subclass only	Outside Package
Private	Yes	No	No	No
Default	Yes	Yes	No	No
Protected	Yes	Yes	Yes	No
Public	Yes	Yes	Yes	Yes

 

Basic Syntax of java :-

public class class_name

{

               public static void main(String args[])

               {

                              System.out.println(“ ”); // statement

               }

}

Explain The Syntax :- 

Class Declaration: 

• public: This is an access modifier. It means that this class is accessible from other classes.

• class: This keyword is used to declare a class in Java.

• ClassName: This is the name of the class. By convention, class names in Java start with an uppercase letter.

Main Method Declaration:

• public: This access modifier means that the method can be called from outside the class.

• static: This means that the method belongs to the class rather than an instance of the class. It can be called without creating an object of the class.

• void: This indicates that the method does not return any value.

• main: This is the name of the method. It's the entry point of any Java application.

• String[] args: This is the parameter passed to the main method. It's an array of strings that stores command-line arguments.

Method Body:

• System.out.println(" ");: This line prints a string to the console.

• System: This is a final class in java.lang package.

• out: This is a static member of the System class and is an instance of PrintStream.

• println(): This is a method of PrintStream class. It prints the argument passed to it, followed by a new line.

Example :-

Output :-