Key Takeaways

• Compound Components solve the “prop explosion” problem by sharing implicit state between parent and child components using the Context API.
• Higher Order Components (HOCs) are functions that take a component and return a new component, primarily used for cross-cutting concerns (logging, auth) and logic reuse.
• Render Props allow components to share code by passing a function as a prop (often render or children) that returns React elements.
• Hooks have largely replaced HOCs and Render Props for logic reuse, but these patterns are still valuable for specific UI composition scenarios and legacy codebases.
• Inversion of Control: All these patterns give more control to the user of the component, allowing them to decide what to render while the library handles how it behaves.

Interactive Flashcards

Test your understanding of React Advanced Patterns. Click to flip!

What is the main benefit of Compound Components?

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Avoids Prop Explosion

It allows parent and child components to share state implicitly (via Context) without passing props through every intermediate level.

What is a Higher Order Component (HOC)?

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A Function

A function that takes a component and returns a new component, used to reuse component logic (e.g., `withAuth(Profile)`).

Why use Render Props over HOCs?

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Dynamic Rendering

Render Props allow you to dynamically determine what to render inside the render method, avoiding static composition and "wrapper hell".

What has largely replaced HOCs and Render Props?

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Custom Hooks

Hooks allow logic reuse without changing the component hierarchy, making code cleaner and easier to debug.

Patterns Cheat Sheet

Pattern	Definition	Best Use Case	Pros	Cons
Compound Components	Components that work together sharing implicit state via Context.	Tabs, Accordions, Form Inputs, Menu Lists.	Clean API, flexible layout.	More boilerplate to setup Context.
Higher Order Components	A function that wraps a component to inject props/logic.	Cross-cutting concerns (Auth, Logging), Class components.	Reusable logic, composition.	“Wrapper Hell”, prop collisions.
Render Props	Passing a function as a prop to share code.	Dynamic rendering logic (e.g., Virtual List, Mouse Tracker).	Explicit data flow, flexible UI.	Verbose syntax (callback hell).
Custom Hooks	Functions that use other hooks to isolate logic.	Data fetching, form handling, event listeners.	No nesting, cleaner code.	Doesn’t render UI itself.

Quick Revision

• Compound Components: Think <select> and <option>. Parent provides Context, children consume it.
• HOC: Think withRouter(Component). Wraps and enhances.
• Render Props: Think <List renderItem={(item) => <Item item={item} />} />. Inversion of control for rendering.
• Hooks: The modern standard. Use useCustomHook() instead of HOCs where possible.

Next Steps

Now that you’ve mastered advanced patterns, it’s time to look at how to optimize your React applications.

React Glossary