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How are React Hooks different from class components in ReactJS?

Last Updated : 15 Feb, 2024
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React Hooks are helpful tools that make building websites and apps with React easier. They simplify how users handle things like data and app behavior, making the code cleaner and easier to understand.

Class components in React are like the old-school way of building parts of your website or app. They use JavaScript classes to structure components, allowing them to manage their own internal state and respond to changes.

Syntax:

  • In class components, you define your component using the class keyword, and you have to extend the React.Component class. With React Hooks, you use regular JavaScript functions to define your components.

Class component:

class MyComponent extends Component {
// State and methods go here
render() {
// JSX template
}
}

React Hooks in functional component

function MyComponent() {
// State and hooks go here
return (
// JSX template
);
}

Exploring Class Components and React Hooks:

  • State Management: In class components, you manage state using the setState() method, which is a bit more verbose. With Hooks, you use the useState() hook to manage state more simply and directly.
  • Lifecycle Methods: Class components have lifecycle methods like componentDidMount(), componentDidUpdate(), etc., which you use to perform actions at different stages of a component’s lifecycle. With Hooks, you use the useEffect() hook to achieve similar behavior, but it’s more flexible and concise.
  • Code Reusability: Class components have higher-order components and render props for code reuse. Hooks allow you to create custom hooks, which are easier to reuse and maintain.
  • Complexity: Class components can sometimes become complex, especially when dealing with state, lifecycle methods, and other features. Hooks promote a more functional approach, which often leads to simpler and more concise code.
  • Performance: Class components can have performance overhead due to the way they handle updates and lifecycle methods. Hooks are designed to be more efficient and can lead to better performance in your React applications.

Difference between Class components and React Hooks:

Class Components React Hooks
Defined with the class keyword and extends React.Component Defined with regular JavaScript functions
Use setState() method Use useState() hook
Have lifecycle methods like componentDidMount(), componentDidUpdate(), etc. Use useEffect() hook
Utilize higher-order components and render props for code reuse Create custom hooks for code reuse
Can become complex due to managing state, lifecycle methods, etc. Promote a more functional approach, leading to simpler code
Can have performance overhead due to lifecycle methods Designed to be more efficient and improve performance


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