Component Composition

In React, component composition is a powerful concept that allows developers to build complex user interfaces by combining smaller, reusable components.

Component composition follows the principle of composition over inheritance, which promotes code reuse and maintainability.

With component composition, you can create a hierarchy of components, where each component is responsible for a specific part of the UI. These smaller components can be combined together to form larger, more complex components.

By breaking down the UI into smaller components and composing them together, you can achieve a modular and flexible architecture.

For example, imagine you are building a social media application with React.

You can break down the UI into smaller components such as Post, Comment, and UserAvatar. These components can be composed together to form the main Feed component that displays the user's feed.

Here's an example of component composition in React:

1import React from 'react';
2
3function Post({ author, content, comments }) {
4  return (
5    <div>
6      <UserAvatar author={author} />
7      <p>{content}</p>
8      <CommentSection comments={comments} />
9    </div>
10  );
11}
12
13function UserAvatar({ author }) {
14  return <img src={author.avatar} alt={author.name} />;
15}
16
17function CommentSection({ comments }) {
18  return (
19    <div>
20      {comments.map((comment) => (
21        <Comment key={comment.id} comment={comment} />
22      ))}
23    </div>
24  );
25}
26
27function Comment({ comment }) {
28  return (
29    <div>
30      <UserAvatar author={comment.author} />
31      <p>{comment.content}</p>
32    </div>
33  );
34}
35
36export default Post;

In the above example, the Post component is composed of the UserAvatar component and the CommentSection component. The CommentSection component is further composed of multiple Comment components.

By using component composition, you can keep your code modular, reusable, and easy to maintain.

Next, we will explore different techniques to optimize the performance of React applications. But before that, let's practice component composition by creating a simple UI using component composition.