My First Program In Java

Java Programming Language Fundamentals of Object-Oriented Programming (Article) Fundamentals of Object-Oriented Programming (Program)

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In this page, we will learn how to write the simple program of java. We can write a simple hello java program easily after installing the JDK.

To create a simple java program, you need to create a class that contains main method. Let's understand the requirement first.

Requirement for Hello Java Example

For executing any java program, you need to

  • install the JDK if you don't have installed it, download the JDK and install it.
  • set path of the jdk/bin directory.
  • create the java program
  • compile and run the java program

Program:

MyFirstJavaProgram {
  public static void main(String []args) { 

     System.out.println("Hello World"); 

   } 
}

Output:

Hello World

Explanation:

Parameters used in the first java program

Let's see what is the meaning of class, public, static, void, main, String[], System.out.println(). 

  • class keyword is used to declare a class in java.
  • public keyword is an access modifier which represents visibility, it means it is visible to all.
  • static is a keyword if we declare any method as static, it is known as static method. The core advantage of static method is that there is no need to create object to invoke the static method. The main method is executed by the JVM, so it doesn't require to create object to invoke the main method. So it saves memory.
  • void is the return type of the method, it means it doesn't return any value.
  • main represents the starting point of the program.
  • String[] args is used for command line argument. We will learn it later.
  • System.out.println() is used print statement. We will learn about the internal working of System.out.println statement later.

This Particular section is dedicated to Programs only. If you want learn more about Java Programming Language. Then you can visit below links to get more depth on this subject.