Lesson 13 of 20
Modules
Split JavaScript into reusable files.
Introduction
Modules export values from one file and import them in another. This keeps code organized and dependencies explicit.
Named exports are useful for several utilities; default exports represent one primary value.
Key insight
Split JavaScript into reusable files.
Example
// math.js
export const add = (a, b) => a + b;
// app.js
import { add } from "./math.js";
console.log(add(2, 3));This example shows the core modules idea in a small, runnable program.
Real-world example
Large web applications separate API clients, UI components and utility modules.
Test yourself
2-question check
1
What is the main idea in Modules?
2
Where can modules be useful?
Ready to check your understanding?
Answer every question, then submit your quiz.
Try it yourself
JavaScript compiler
Runs in your browser. Nothing is sent to a server.
Output appears here
Practice challenge
Export a function that converts minutes to seconds.