Creating a Command-Line Application with IntelliJ IDEA
Tags: java, intellijidea, cli, beginners
Published: 2023-03-18 20:02:58

Are you looking to learn Java but feeling overwhelmed with the idea of creating complex graphical user interfaces? Don't worry, you're not alone. Building GUI applications can be complicated, especially for beginners. That's why starting with command-line applications can be a great way to learn the language properly before moving on to more complex projects.

In this tutorial, we'll guide you through the process of creating and running a basic command-line application using IntelliJ IDEA. By the end of this tutorial, you'll have a solid understanding of how to write and execute a simple Java program on the command line.

## **Creating a Project**

The first step is to create a new project in IntelliJ IDEA. To do this, open the IDE and click on `"Create New Project."` Select `"Java"` as the project type, and then click `"Next`." On the next screen, choose the project SDK (version of Java) that you want to use, and then click `"Next"` again. Finally, give your project a name and select a directory to save it in.

## **Setting Up the Base Package**

Once you've created the project, the next step is to set up the base package. A package is a way to organize your code into logical groups. To create a package, right-click on the "src" directory in your project and select "New" > "Package." Give your package a name, such as "com.yourname.app," and then click "OK."

## **Writing and Executing the Main Method**

Now that the project is set up, it's time to write some code. In Java, the entry point for any program is the main method. To create the main method, right-click on your package and select "New" > "Java Class." Give your class a name, such as "App," and then click "OK." IntelliJ IDEA will automatically generate some boilerplate code for you, including the main method.

In the main method, add the following code:

```java
public static void main(String[] args) {
    System.out.println("Hello, world!");
}
```

This code simply prints "Hello, world!" to the terminal when the program is run.

To run the program, right-click on the main method and select "Run 'App.main()'." IntelliJ IDEA will compile the code and execute the program, printing "Hello, world!" to the terminal.

## **Using the System Class to Print to the Terminal**

In the previous step, we used the System class to print to the terminal. The System class is part of the Java standard library and provides access to the system resources, including the console. The println method is a member of the System class and is used to print a string to the console.

## **Adding Comments to Code**

Finally, it's important to add comments to your code to make it more readable and understandable. Comments are lines of code that are ignored by the compiler and are used to explain what the code does. To add a comment, simply start a line with two forward slashes (//). Anything following the slashes will be ignored by the compiler.

## **Conclusion**

Congratulations, you've successfully created and run a basic Java command-line application using IntelliJ IDEA! We hope this tutorial has given you a solid foundation in Java programming and that you're ready to tackle more complex projects. Remember, starting with command-line applications is a great way to learn Java properly before moving on to desktop or mobile applications. Happy coding!