Your First Node.js Program
📌 Covered in this chapter:
Creating app.js · node app.js · console.log() · process.argv · process.cwd() · process.version
Write, save, and run your very first Node.js file, and explore console.log() and the built-in process object.
1Your First Node.js Program — What You'll Learn
Write, save, and run your very first Node.js file, and explore console.log() and the built-in process object.
Here's everything this chapter covers, in the order you'll learn it:
- Creating an app.js file
- Running a file with node app.js
- console.log() basics
- Reading command-line output
- process.exit()
- The process global object
- process.argv (command-line arguments)
- process.cwd() (current working directory)
- process.version
- Basic debugging with console.log
2Working Example
💻 Example: Your First Node.js Program
JavaScript
▶ Run in Compiler
console.log("Hello, Node.js!");
console.log("Version:", process.version);
console.log("Arguments:", process.argv);3Best Practices & Common Pitfalls
💡 Key things to remember:
- process.argv[0] is the node binary path, process.argv[1] is your file path — your actual arguments start at index 2.
- console.log() accepts multiple comma-separated arguments and prints them space-separated, which is handy for quick debugging.
❓ Frequently Asked Questions (FAQ)
Q What's the most important thing to understand about your first node.js program?
Focus on: Creating app.js · node app.js · console.log() · process.argv · process.cwd() · process.version. These are the core building blocks this chapter's examples are built around, and they show up repeatedly in later chapters of this course.
Q Do I need external npm packages for your first node.js program?
Only where explicitly shown in the code examples above (like Express, Zod, or Socket.IO) — otherwise, this chapter relies entirely on Node.js's own built-in capabilities.