Design Converter
Education
Last updated on Jan 15, 2025
Last updated on Jan 15, 2025
Software Development Executive - II
In JavaScript, managing modules effectively is crucial for building maintainable and scalable applications. When working with JavaScript modules, default, and named imports are two primary ways to bring external code into your project.
This blog will help you understand the nuances of default imports, and named imports, and how to decide between the two for specific scenarios. By mastering these concepts, you'll learn to share code, optimize your import methods, and code efficiently.
JavaScript modules allow you to organize your code into smaller, reusable pieces. These modules can reside in different files or even within the same file, making them highly flexible for managing functionality and components. JavaScript modules support two primary ways of exporting values: default exports and named exports.
A default export allows you to export one primary value from a module. When using a default keyword, you're telling JavaScript that this is the main item being exported from the file. Each module can have only one default export.
Here’s how you create a default export in a js file:
1// file: button.js 2export default function ButtonComponent() { 3 return `<button>Click Me!</button>`; 4}
A default import is the way to import this primary value from a module. When importing a default export, you can assign it any name since it’s the only export.
1// file: app.js 2import MyButton from './button.js'; // Importing the default export 3console.log(MyButton());
In this example, even though the export default was named ButtonComponent, the default import allows renaming it to MyButton.
Named exports allow you to export multiple values from the same module. These are explicitly named exports, meaning each exported value retains its name and must be referenced accordingly.
1// file: utilities.js 2export function add(a, b) { 3 return a + b; 4} 5 6export function subtract(a, b) { 7 return a - b; 8}
When using named imports, you use curly braces to specify which exported values you want to use. The names must match the exact names of the exported functions, variables, or components.
1// file: app.js 2import { add, subtract } from './utilities.js'; // Named imports 3console.log(add(5, 3)); // Outputs: 8 4console.log(subtract(5, 3)); // Outputs: 2
If you need all the named exports, you can use a wildcard * as shown:
1import * as Utils from './utilities.js'; 2console.log(Utils.add(5, 3)); // Outputs: 8
• Default imports: No curly braces, any name can be assigned.
• Named imports: Use curly braces and require exact names.
• A file can have only one default export.
• A file can have as many named exports as needed.
• Use default export for the main functionality of a single file (e.g., a button component).
• Use named exports when exporting multiple things (e.g., utility functions) from one file.
You can combine default and named imports in the same statement:
1// file: app.js 2import ButtonComponent, { add, subtract } from './utilities.js'; 3console.log(ButtonComponent()); 4console.log(add(2, 3));
Choosing between named import vs default import depends on the nature of your javascript modules. A default export is ideal for one default export per module, while named exports allow you to export multiple values from a single file. By understanding these distinctions, you’ll not only code efficiently but also make your projects more maintainable. Remember to always check the syntax and the module structure to avoid errors.
Embrace both default and named imports to unlock the full potential of modular development in JavaScript.
Tired of manually designing screens, coding on weekends, and technical debt? Let DhiWise handle it for you!
You can build an e-commerce store, healthcare app, portfolio, blogging website, social media or admin panel right away. Use our library of 40+ pre-built free templates to create your first application using DhiWise.