Callbacks

The oldest way Node.js handled async tasks. Can lead to “callback hell”.

Overview

The oldest way Node.js handled async tasks. Can lead to “callback hell”.

Code Example

import fs from "node:fs";\nfs.readFile("data.txt", (err, data) => {\n  if (err) throw err;\n  console.log(data);\n});

Web Development Context

In modern web development, understanding Callbacks 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.