How to console java echo hello you (Java Programming Language)

Implementation of a Java application program involves a following step. They include:1. Creating the program2. Compiling the program3. Running the program

• Creating ProgramWe can create a program using Text Editor (Notepad) or IDE (NetBeans)

File Save : d:\Test.java• Compiling the programTo compile the program, we must run the Java compiler (javac), with the name of the source file on “command prompt” like as follows

If everything is OK, the “javac” compiler creates a file called “Test.class” containing byte code of the program.

• Running the programWe need to use the Java Interpreter to run a program.

Java is easy to learn, and its syntax is simple and easy to understand. It is based on C++ (so easier for programmers who know C++).

The process of Java programming can be simplified in three steps:

The below-given program is the most simple program of Java printing “Hello World” to the screen. Let us try to understand every bit of code step by step.

Time Complexity: O(1)

Space Complexity: O(1)

The “Hello World!” program consists of three primary components: the HelloWorld class definition, the main method, and source code comments. The following explanation will provide you with a basic understanding of the code:

This line uses the keyword class to declare that a new class is being defined.

It is an identifier that is the name of the class. The entire class definition, including all of its members, will be between the opening curly brace “{” and the closing curly brace “}“.

In the Java programming language, every application must contain a main method. The main function(method) is the entry point of your Java application, and it’s mandatory in a Java program. whose signature in Java is:

Like in C/C++, the main method is the entry point for your application and will subsequently invoke all the other methods required by your program.

The next line of code is shown here. Notice that it occurs inside the main() method.

This line outputs the string “Hello, World” followed by a new line on the screen. Output is accomplished by the built-in println( ) method. The System is a predefined class that provides access to the system, and out is the variable of type output stream connected to the console.

They can either be multiline or single-line comments.

This is a single-line comment. This type of comment must begin with // as in C/C++. For multiline comments, they must begin from /* and end with */.

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I will assume that you're either reading this article as a beginner to the Java programming language or you're here to remember the good old Hello World program. Either way, it is going to be simple and straight to the point.

This article won't only include the hello world program in Java, we'll also talk about some terminologies you should know as a beginner learning to use Java.

To follow along, you'd need an integrated development environment (IDE). This is where you write and compile your code. You can install one on your PC or you can use any online IDE if you don't want to go through with the installation process.

In this section, we'll create a simple Hello World program. We'll then break it down so you'd understand how it works.

Here's the code:

The code in the example above will print "Hello World!" in the console. This is commented out in the code. We'll talk about comments shortly.

Let's break down the code.

Classes act as the building blocks for the overall application in Java. You can have separate classes for different functionalities.

Classes can also have attributes and methods that define what the class is about and what it does.

An example would be a Human class. It can have attributes like hair color, height, and so on. It can have methods like run, eat, and sleep.

In our Hello World program, we have a class called HelloWorld. As a convention, always start the name of your classes with an uppercase letter.

To create a class, you use the class keyword, followed by the name of the class. Here's an example using our Hello World program:

Every Java program must have a main method. When the Java compiler starts executing our code, it starts from the main method.

Here's what the main method looks like:

In order to keep this article simple, we won't discuss other keywords found above like public, static, and void.

We use the System.out.println() statement to print information to the console. The statement takes an argument. Arguments are written between the parentheses.

Here's the syntax:

In our case, we passed in "Hello World!" as an argument. You'll notice that the text is surrounded by quotation marks. This tells the compiler that the argument is a string. Strings in programming are just a collection of characters – the same way we'd write regular text, but they must be in quotes.

Here's what our code looks like:

When we run this code, "Hello World" will be printed.

It won't be printed inside the code block above. I used // Hello World! as a way to show you the output of the code. That part of the code will not be executed by the compiler because it is a comment.

We use two forward slashes (//) to start a single line comment in Java.

In this article, we talked about the Hello World program in Java.