Lead level: Lifecycle Methods and Hooks in React

As a lead developer, you are expected to guide your team in building robust, maintainable, and scalable applications using React. Understanding advanced concepts and best practices in React Hooks and lifecycle methods is crucial. This article covers essential hooks, custom hooks, and advanced hook patterns, such as managing complex state with useReducer and optimizing performance with useMemo and useCallback.

Introduction to React Hooks

React Hooks, introduced in React 16.8, allow you to use state and other React features without writing class components. They provide a more functional and modular approach to managing component logic.

Key Benefits of Hooks

1. Cleaner Code: Hooks simplify the code by enabling state and lifecycle methods directly in functional components.
2. Reusability: Custom hooks allow the extraction and reuse of stateful logic across multiple components.
3. Modularity: Hooks provide a more straightforward API to manage component state and side effects, promoting modular and maintainable code.

Essential Hooks

useState

useState is a hook that lets you add state to functional components.

Example:

import React, { useState } from 'react';

const Counter = () => {
  const [count, setCount] = useState(0);

  return (
    <div>
      <p>You clicked {count} times</p>
      <button onclick="{()"> setCount(count + 1)}>Click me</button>
    </div>
  );
};

export default Counter;

In this example, useState initializes the count state variable to 0. The setCount function updates the state when the button is clicked.

useEffect

useEffect is a hook that lets you perform side effects in functional components, such as fetching data, directly interacting with the DOM, and setting up subscriptions. It combines the functionality of several lifecycle methods in class components (componentDidMount, componentDidUpdate, and componentWillUnmount).

Example:

import React, { useState, useEffect } from 'react';

const DataFetcher = () => {
  const [data, setData] = useState(null);

  useEffect(() => {
    fetch('https://api.example.com/data')
      .then(response => response.json())
      .then(data => setData(data));
  }, []);

  return (
    <div>
      {data ? <pre class="brush:php;toolbar:false">{JSON.stringify(data, null, 2)}

: 'Loading...'}