MemotivaBack to topic
Component Lifecycle

Component Lifecycle

Learn how to optimize your React applications for performance. This section covers performance optimization techniques, component lifecycle methods, and best practices to ensure your applications run smoothly and efficiently.

6 audio · 1:04

Nortren·

What is the component lifecycle in class components?

0:12
The lifecycle has three phases: mounting, updating, and unmounting. Key methods include constructor, render, componentDidMount, componentDidUpdate, and componentWillUnmount. Hooks in functional components cover the same scenarios.

What is componentDidMount used for?

0:10
componentDidMount runs once after a class component is inserted into the DOM. It is typically used for data fetching, setting up subscriptions, or integrating with third-party DOM libraries.

What is componentDidUpdate used for?

0:11
componentDidUpdate runs after every update of a class component except the first render. It receives the previous props and state, allowing comparison with current values before performing side effects like fetching new data.

What is componentWillUnmount used for?

0:10
componentWillUnmount runs just before a class component is removed from the DOM. It is used to clean up subscriptions, cancel network requests, and clear timers to prevent memory leaks.

What is a stateless component?

0:10
A stateless component is one that does not manage its own state and simply renders output based on props. In modern React, any functional component that does not use state hooks is effectively stateless.

What is a stateful component?

0:11
A stateful component is one that manages internal state, either through useState and other hooks in a functional component or through this.state in a class component. It re-renders when its state changes. ---