Non-blocking I/O

Node.js does not wait for file or network operations to finish before moving to the next line of code.

Overview

Node.js does not wait for file or network operations to finish before moving to the next line of code.

Code Example

import fs from "node:fs";\nfs.readFile("file.txt", () => console.log("Done reading"));\nconsole.log("This runs FIRST!");

Web Development Context

In modern web development, understanding Non-blocking I/O is crucial. Node.js is widely used for building APIs, real-time applications, and microservices. Mastery of this concept allows you to build efficient, scalable, and secure backend systems.

Common Mistakes

• Blocking the event loop with heavy synchronous tasks.
• Exposing secrets in code instead of environment variables.
• Forgetting to handle promise rejections.

Next Steps

To solidify your understanding, review the related references and try out the practice challenges.