ES Modules (named vs default), re-exports
Understand named vs default exports/imports and how to re-export to build tidy module boundaries.
ES Modules (named vs default), re-exports is a free TypeScript Academy lesson on CoddyKit. This is lesson 1 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the TypeScript Academy learning path, and your progress syncs across the web and the CoddyKit app. The TypeScript Academy course includes 3 lessons in total.
Intro
Goal: Use ES Modules confidently. You will export/import named and default symbols, then compose them with re-exports for tidy public APIs.
Named exports/imports
Named exports use export before declarations; import them with braces: import { name }.
// file: math.ts
export function add(a: number, b: number): number { return a + b }
export const PI = 3.14159
// file: app.ts
import { add, PI } from "./math"
console.log(add(2, 3), PI) // 5 3.14159Default export/import
Default export is a module’s primary value. Import it without braces: import Foo from "./mod".
// file: greet.ts
export default function greet(name: string) { console.log(`Hello, ${name}`) }
// file: app.ts
import greet from "./greet"
greet("Ada")Default + named together
You can combine one default with multiple named exports in a module and import both together.
// file: color.ts
export default "black"
export const palette = [ "red", "green", "blue" ]
// file: app.ts
import baseColor, { palette } from "./color"
console.log(baseColor, palette.length)Re-exports (barrels)
Re-exports (export { x } from / export * from) create a barrel, so consumers import from a single entry.
// file: math/add.ts
export const add = (a: number, b: number) => a + b
// file: math/index.ts (barrel)
export { add } from "./add"
export * from "./more"
// file: app.ts
import { add } from "./math"
console.log(add(1, 2))Tips & pitfalls
Tips:
- Prefer named exports for discoverability and consistent renames.
- Use default export for a module’s single “main” thing.
- Build barrels at package boundaries; avoid circular imports.
Default import check
Quick check: Which import matches a default export?
Recap
Recap: Use named for multiple exports, default for a single primary value, and re-exports to present a clean entry point.
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Frequently Asked Questions
Is the “ES Modules (named vs default), re-exports” lesson free?
Yes — the full text of “ES Modules (named vs default), re-exports” is free to read here on the web. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the TypeScript Academy course, upgrade to CoddyKit PRO. The TypeScript Academy course includes 3 lessons in total.
What will I learn in “ES Modules (named vs default), re-exports”?
Understand named vs default exports/imports and how to re-export to build tidy module boundaries. You practise TypeScript Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start TypeScript Academy?
No prior experience is required. TypeScript Academy on CoddyKit is structured for beginners through advanced learners, so you can start here or from the beginning and move at your own pace. This is lesson 1 of 3.
How long does the “ES Modules (named vs default), re-exports” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this TypeScript Academy lesson?
Yes. Every TypeScript Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- ES Modules (named vs default), re-exports
- Ambient declarations (.d.ts) & third-party typings
- Path mapping & module resolution