How to Run a Node.js Script

Node.js is a powerful JavaScript runtime that allows developers to execute JavaScript code on the server side. Running a Node.js script is straightforward, and this tutorial will guide you through the steps involved in executing your Node.js applications from the command line.

1. Prerequisites

Before running a Node.js script, ensure that you have Node.js installed on your system. You can check if it is installed by running:

node -v

This command will display the version of Node.js installed. If you need to install Node.js, refer to appropriate installation guides for your operating system.

2. Creating a Simple Node.js Script

Open your terminal and create a new JavaScript file, e.g., app.js:

nano app.js

Add the following code to test your setup:

console.log('Hello, Node.js!');

Save and exit the text editor.

3. Running the Node.js Script

You can run your Node.js script using the following command:

node app.js

When you execute this command, the output should display:

Hello, Node.js!

4. Running Scripts with Command-Line Arguments

Node.js also allows you to pass command-line arguments to your scripts. For example, modify your script:

const args = process.argv.slice(2);
console.log('Arguments:', args);

Now, run it with arguments:

node app.js arg1 arg2

This will log the arguments passed to the script.

5. Using Nodemon for Automatic Restarts

For development purposes, you can use nodemon to automatically restart your Node.js application when file changes are detected:

npm install -g nodemon

Then run your script with:

nodemon app.js

6. Conclusion

By following this tutorial, you have learned how to run a Node.js script using the command line interface. Knowing how to execute scripts efficiently is vital for effective development and testing. Continue to explore Node.js features and tools to enhance your coding experience!

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Dorian Kane

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