Export vs Export Default in React: Understanding the Key Differences

Understanding the difference between export and export default in React is crucial for building reusable and maintainable components. While both serve to share code, they have distinct purposes and implications for how your components are imported and used.

What is Export?

The export keyword in React is used to make individual components, functions, or variables accessible outside the current file. You can export multiple items from a single file, making it convenient for organizing your code into modules.

// MyComponent.js
export const MyComponent = () => {
  // ... component logic ...
}

export function sayHello() {
  console.log("Hello!");
}

In this example, MyComponent and the sayHello function are both exported. To use them in another file, you would import them specifically:

// App.js
import { MyComponent, sayHello } from './MyComponent';

const App = () => {
  return (
    <div>
      <MyComponent />
      <button onClick={sayHello}>Say Hello</button>
    </div>
  );
}

What is Export Default?

export default is used to designate a single item within a file as the primary export. This is often used for components that are the primary focus of a file. Only one export default can be used per file.

// MyComponent.js
const MyComponent = () => {
  // ... component logic ...
}

export default MyComponent; 

In this example, MyComponent is the default export. You can import it without curly braces:

// App.js
import MyComponent from './MyComponent';

const App = () => {
  return (
    <div>
      <MyComponent />
    </div>
  );
}

Key Differences Between Export and Export Default

When to Use Export

• When you want to export multiple items from a file.
• When you need to be explicit about which components or functions you’re importing.

When to Use Export Default

• When you have a single primary component or function in a file.
• When you want to make it easy to import the main item from the file.

“Export vs Export Default in React: A Practical Example”

Let’s consider a scenario where you’re building a simple blog application. You have a Post component that displays individual blog posts, and a PostList component that displays a list of posts.

Option 1: Using export default

// Post.js
export default const Post = ({ title, content }) => {
  return (
    <div>
      <h3>{title}</h3>
      <p>{content}</p>
    </div>
  );
};

// PostList.js
export default const PostList = ({ posts }) => {
  return (
    <ul>
      {posts.map(post => (
        <li key={post.id}>
          <Post title={post.title} content={post.content} />
        </li>
      ))}
    </ul>
  );
};

// App.js
import Post from './Post';
import PostList from './PostList';

const App = () => {
  const posts = [
    { id: 1, title: "Post 1", content: "Content for Post 1" },
    { id: 2, title: "Post 2", content: "Content for Post 2" },
  ];

  return (
    <div>
      <PostList posts={posts} />
    </div>
  );
};

In this example, Post and PostList are both exported as default exports. This approach is straightforward if you primarily want to use these components as the main elements within their respective files.

Option 2: Using export

// Post.js
export const Post = ({ title, content }) => {
  return (
    <div>
      <h3>{title}</h3>
      <p>{content}</p>
    </div>
  );
};

// PostList.js
export const PostList = ({ posts }) => {
  return (
    <ul>
      {posts.map(post => (
        <li key={post.id}>
          <Post title={post.title} content={post.content} />
        </li>
      ))}
    </ul>
  );
};

// App.js
import { Post, PostList } from './Post';

const App = () => {
  const posts = [
    { id: 1, title: "Post 1", content: "Content for Post 1" },
    { id: 2, title: "Post 2", content: "Content for Post 2" },
  ];

  return (
    <div>
      <PostList posts={posts} />
    </div>
  );
};

Here, both Post and PostList are named exports, giving you more control over importing them individually. This approach is helpful if you might have other related components in these files.

“Export vs Export Default in React: Best Practices”

Generally, it’s recommended to use export default for the primary component or function within a file and use export for other related elements. This approach helps maintain code clarity and promotes modularity.

For example, in a file named Button.js, you might use export default for the Button component and use export for any helper functions or styles associated with that component.

By applying these principles, you can ensure your React code is well-organized, maintainable, and scalable.

“Export vs Export Default in React: FAQ”

1. Can I use both export and export default in the same file?

Yes, you can. You can have multiple export statements and one export default statement in a file.

2. What if I don’t use any export statements in a file?

If you don’t use any export statements, the code within that file will be inaccessible from other files.

3. Can I change the default export later?

Yes, you can change the default export at any time, as long as there is only one export default statement in the file.

4. What if I import a file that uses export default but I want to use a named export?

If you import a file with a default export, you can access named exports using curly braces after the imported name.

5. Can I export multiple components with the same name?

You can’t export multiple components with the same name using export default. You can, however, use different names for named exports.