First Java Program - Hello World

It's always exciting to write your first program and execute it without error. In this post you will learn to write your first java program.

Pre-Requisite Softwares :

1. Java SE Development Kit or JDK  - It is generally a Java Software which you need to install on your system before writing any code in Java. And after installing java set Java Path in your environment variables.

  • Download Latest Java Version from following link - Java Download
2. Java IDE or Text Editor - You need to have any text editor to write Java code. You can use anyone from following Netbeans, Intellij, Eclipse, Notepad or Notepad++ etc.

Creating Hello World Program
  • Declare a class 'MyFirstProgram'
  • Declare the main method public static void main()
  • And print a string "Hello World" using System.out.println()
Hello World Program

// Class
class MyFirstProgram {
 
 // Main method
 public static void main(String[] args) {
  
  // Print Hello World
  System.out.println("Hello World");
 } 

}




Java Keywords used in 'Hello World' Program
  • class keyword is used to declare a class.
  • Public is an access modifier which defines main method's accessibility. Public means main method is global or accessible to all other classes in the project.
  • static is a keyword in java, when static is used with any method then it is called static method. Static method can be called without creating the object of the class.
  • main is the method name and also the execution point of any program. Main method is required to execute the program.
  • String[] args is an array of string is basically for command line arguments.
  • System.out.println() is used to print any statement. 
    • System is a class
    • out is the object of PrintStream class
    • println() is method of PrintStream class

Run the First Program:
  • If you are using Eclipse then you can run this program by just clicking the green play button displayed on the top bar. 
  • Or right click anywhere in the class and click 'Run as Java Program'.

Output:
  • Hello World - will be displayed in the console


JDK, JRE & JVM  << Previous      ||      Next >>  Java Variables


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Author: Vaneesh Behl
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