Node Tactics

Basics

Node.js Running Code

Running Node.js Scripts

Node.js scripts run via node command or REPL with .js files.

Introduction to Running Node.js Scripts

Running Node.js scripts is a fundamental skill for any developer working with Node.js. In this guide, we'll explore the primary ways to execute Node.js code: using the node command and the Node.js Read-Eval-Print Loop (REPL).

Running Scripts with the Node Command

The most common way to run a Node.js script is by using the node command followed by the filename. This approach requires a JavaScript file with the .js extension.

To execute this script, open your terminal and navigate to the directory containing app.js. Then run the following command:

This command will output Hello, Node.js! to the console, demonstrating a successful execution of your Node.js script.

Using the Node.js REPL

The Node.js REPL (Read-Eval-Print Loop) is an interactive shell that allows you to execute JavaScript code line-by-line. It's useful for testing small code snippets and debugging.

After entering the REPL, you can type JavaScript code directly. For example, to print a message:

The REPL will immediately execute your code and display the output:

Welcome to the Node.js REPL!

Conclusion

Running Node.js code is straightforward, whether you use the node command with a JavaScript file or the interactive REPL. Mastering these techniques is an essential step for any Node.js developer.

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