Introduction to React Hooks
React Hooks are functions that allow functional components to use state and other React features without writing a class. They were introduced in React 16.8 to address common issues with class components, such as managing state and lifecycle methods.
- useState: Manages state in functional components, allowing them to have stateful behavior.
- useEffect: Performs side effects in functional components, such as data fetching or DOM manipulation, after rendering.
- useContext: Accesses context values in functional components, providing a way to share data across the component tree.
- useReducer: Alternative to useState, especially useful for managing complex state logic in functional components.
- useCallback: Memoizes callback functions, optimizing performance by preventing unnecessary re-renders in child components.
- useMemo: Memoizes computed values, improving performance by caching expensive calculations.
- useRef: Creates a mutable ref object, useful for accessing and managing references to DOM elements or other values across renders.
- useLayoutEffect: Similar to useEffect but runs synchronously after all DOM mutations, ideal for tasks requiring precise DOM measurements or manipulations.
Example: Here’s an example of using the useState hook in a functional component:
import React, { useState } from 'react';
function Counter() {
const [count, setCount] = useState(0);
return (
<div>
<p>Count: {count}</p>
<button onClick={() => setCount(count + 1)}>Increment</button>
</div>
);
}
export default Counter;
Getting Started with React
ReactJS, often referred to as React, is a popular JavaScript library developed by Facebook for building user interfaces. It emphasizes a component-based architecture, where UIs are built using reusable components. React uses a declarative syntax to describe how UIs should look based on their state, simplifying development and enhancing code readability.
React also utilizes a virtual DOM to optimize rendering performance by minimizing actual DOM manipulations. React’s unidirectional data flow and rich ecosystem of libraries and tools have made it a go-to choice for frontend development, especially in building single-page applications (SPAs).
Table of Content
- Why ReactJS ?
- Setting Up Your Development Environment
- Understanding React Components
- Creating Your First React Component
- JSX (JavaScript XML)
- Working with Props and State
- Handling Events:
- Conditional Rendering
- Lists and Keys
- Styling React Components
- Introduction to React Hooks
- Building a Simple React Application
- Component Lifecycle
- React Router
- Managing State with Context API