When should I use a default export vs a named export?

Industry standard at TheCodeForge suggests using named exports for utilities and constants because they force consistent naming across the codebase. Use default exports only for the 'Single Responsibility' of a file, like a specific React component. Avoid 'mixing' both in one file as it makes the import syntax cumbersome for other developers.

Can I import a CommonJS module in an ES Module file?

Yes, in Node.js, you can use `import defaultExport from './file.cjs'`. Node will wrap the `module.exports` of the CJS file as the default export of the ESM import. However, you cannot use `require()` inside an ES Module file; you must stick to `import`.

Why do I get 'Uncaught SyntaxError: Cannot use import statement outside a module'?

This happens in the browser when you forget to add `type='module'` to your ` ` tag. Without this attribute, the browser treats the file as a legacy script where 'import' is a reserved word but not a functional command.

Does 'import' copy the value or create a reference?

ES Modules provide 'live bindings.' If a module exports a variable and then changes its value, the importing module sees that change. This is a major difference from CommonJS, which exports a snapshot/copy of the value at the time of the require call.

JavaScript Intermediate

Modern JavaScript Modules: Mastering import and export

📅 March 05, 2026 ⏱ 3 min read 🎯 Intermediate

Where developers are forged. · Structured learning · Free forever.

📍 Part of: Advanced JS → Topic 10 of 27

A deep dive into JavaScript Modules (ESM) — learn named vs.

⚙️ Intermediate — basic JavaScript knowledge assumed

In this tutorial, you'll learn

A deep dive into JavaScript Modules (ESM) — learn named vs.

Named exports (export const X) require curly braces and support Tree Shaking better than default exports.
Default exports (export default X) are best for primary classes or components; they don't require braces.
Dynamic import() is a function that returns a Promise—ideal for code splitting and reducing initial bundle size.

✦ Plain-English analogy ✦ Real code with output ✦ Interview questions

⚡Quick Answer

ES Modules (ESM) use export to expose functionality and import to consume it. Use curly braces for named exports: import { helper } from './api.js'. Use no braces for default exports: import Consumer from './service.js'. In browsers, use