How to Code Hello World in Java
A “Hello, World!” program is a simple computer program that outputs “Hello, World!” on a display device. It is often used to illustrate the basic syntax of a programming language for a working program. The phrase has become a tradition for new programmers who are learning to code. The first known version of the “Hello, World!” program was created by Brian Kernighan in 1972, as part of the development of the C programming language.
Java is a programming language and computing platform used for creating and running applications. It was first released by Sun Microsystems in 1995 and is now maintained by Oracle Corporation. It is used to create applications for a wide range of devices, including computers, mobile phones, and television set-top boxes Java is one of the most popular programming languages becoming the go to language for building Android apps.
In this tutorial, we will learn how we to write the classic Hello World program using the Java programming language.
Requirements
To write and run the code provide in this tutorial, you will need to have:
- The Java JDK or JRE installed on your machine.
- A code editor of your choice.
Java Hello World Program.
Start by creating a file ending in .java
extension to store the source code for your Hello world program.
$ touch hello_world.java
Edit the file with your text edito:
$ nano hello_world.java
Finally, add the source code as shown below:
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}
Let us break down the code above.
public class HelloWorld
- This line declares a class calledHelloWorld
. Thepublic
keyword indicates that the class is visible to other classes.public static void main(String[] args)
- This line declares the main method of the program. Themain
method is where the program starts when it is run. Thepublic
keyword indicates that the method is visible to other classes. Thestatic
keyword indicates that the method can be called without creating an instance of the class. Thevoid
keyword indicates that the method does not return any value. TheString[] args
is an array of strings that can be passed to the program when it is run.System.out.println("Hello, World!")
- FInally, we print the string “Hello, World!” to the screen using this block. TheSystem
class is part of the Java language library and provides access to the system’s input and output. Theout
field is aPrintStream
object that is used to print output to the screen. Theprintln
method prints a line of text to the screen and moves the cursor to the beginning of the next line.
To run the code above, save the file and close your text editor. In the termninal, run the java compiler and pass the file name as shown:
java hello_world.java
Running the command above should compile the program and print the string “Hello, World!” on the console.
Conclusion
In this tutorial, you discovered the basics of creating and running a Hello World program using the Java programming language. You also discovered the anatomy of the Hello world program and what each section represents.
We hope you enjoyed this post.