React Best Practices Every Developer Should Know

The more I dive into React.js, the more I appreciate its capabilities. There’s no doubt it’s one of the most loved and powerful front-end JavaScript libraries out there. Recently, React’s improvements have benefited not just developers, but also users of applications built with it.

In a previous article, I explored various React Hooks with code samples and detailed explanations. This time, I’ll share some valuable insights I’ve learned while building React apps, optimized through the use of React Hooks. We’ll clear up common myths, simplify complex concepts, and help you write cleaner, more efficient React code.

What We’ll Cover:

• How this guide will help you
• Prerequisites
• Best practices for managing state
• Avoiding misuse of useState
• Computing values without side effects
• Ensuring unique keys
• Using useEffect efficiently

How Will This Guide Benefit You?

Imagine I give you a knife and ask you to cut shapes out of fabric. You’d manage, but it’d take time and effort. Now, what if I hand you a pair of sharp scissors instead? Cutting would become easier and faster, right?

This guide is like those scissors. It’ll teach you how to simplify your development process in React, reduce unnecessary struggles, and optimize performance. We’ll focus on the key aspects of React Hooks, offering practical do’s and don’ts.

Prerequisites

There’s just one main prerequisite: you should have used React Hooks at least once, ideally by building an app that takes advantage of them. This article is for anyone looking to maximize the potential of React Hooks.

1. React State Must Be Immutable

Ever wondered why React emphasizes immutability? As a new developer, JavaScript’s mutable nature may seem harmless—we add and remove properties from objects and modify arrays with ease. However, in React, immutability ensures consistency.

When you directly mutate state, React may fail to detect changes, causing your UI to update incorrectly. The key is to create new copies of your data instead of mutating the original.

For instance, if you’re adding a new user, rather than modifying the existing array, create a new one:

const updatedUsers = [...users, newUser];        

This way, React notices the state change and re-renders the component accordingly.

2. Don’t Use useState for Everything

I used to think useState was the answer for everything. But overusing it can complicate your code and reduce efficiency.

Before adding something to useState, ask yourself these questions:

• Is the value simple enough to derive during render?
• Does a library already handle this state for you?
• Does this value need to trigger a re-render?

If the answer is “no” to all, you may not need useState. Explore alternatives like server state (handled by libraries like React Query) or URL state (managed by hooks like useLocation from React Router).

3. Derive Values Without State

You don’t always need to store derived values in state. If a value can be calculated from existing state or props, compute it directly during render.

For example, if you’re formatting a date, there’s no need to add it to state:

const formattedDate = new Date(date).toLocaleDateString();        

This approach simplifies your component and avoids unnecessary state updates, keeping your code clean and efficient.

4. Compute Values Without Effects

Stop using useEffect for simple computations. If your value is derived from props or state and doesn't involve side effects, calculate it directly during render. For expensive computations, wrap them in useMemo to boost performance:

const expensiveValue = useMemo(() => computeExpensiveValue(data), [data]);        

This way, you avoid recalculations on every render and enhance performance for complex operations.

5. Keys Should Be Unique

I’m guilty of using array indexes as keys in lists. But doing so can cause bugs, as React relies on unique keys to identify list items.

Always generate unique IDs, like this:

const itemsWithId = items.map(item => ({ ...item, id: generateUniqueId() }));        

Unique keys allow React to update and manage lists efficiently, ensuring smooth rendering performance.

6. Use useEffect Sparingly

useEffect is a powerful tool, but overusing it can lead to messy code. For handling side effects like data fetching, libraries like TanStack Query or SWR offer a more elegant solution.

Before using useEffect, consider:

• Can you derive the value directly from props or state?
• Can you handle it with event listeners or handlers instead?
• Is server-side fetching a better option?

The goal is to minimize the use of useEffect for better code organization and performance.

Conclusion

React is a powerful library, but using it effectively is key to building fast, maintainable apps. By following these best practices, you’ll write cleaner code, avoid common pitfalls, and get the most out of React Hooks.

Thanks for reading, and happy coding! 🎉