What are the main approaches and mechanisms for ensuring modularity used in Node.js?

In Node.js, modularity is provided by several main mechanisms:

• CommonJS modules — the standard way of organizing code, where each file is a module with module.exports and require() for importing.

• ES6 modules (ESM) — a modern standard using export and import.

• npm packages — allow sharing and reusing code, managing dependencies.

• Code organization patterns — for example, dividing into controllers, services, models.

• Use of bundlers (Webpack, Rollup) — for combining modules into a single file.

Example of a CommonJS module:

// math.js
function add(a, b) {
  return a + b;
}
module.exports = { add };

// app.js
const math = require('./math');
console.log(math.add(2, 3));

Example of an ES6 module:

// math.mjs
export function add(a, b) {
  return a + b;
}

// app.mjs
import { add } from './math.mjs';
console.log(add(2, 3));