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REACT Tutorial
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Component Lifecycle

In the dynamic world of React, understanding the lifecycle of components is crucial for building efficient and scalable applications. Whether you’re a beginner or an experienced developer, this comprehensive guide will walk you through the intricacies of the React component lifecycle. Let’s delve into the different phases and explore how components mount, update, and unmount.

The Birth of a Component: Mounting

1. Constructor:

Every React component has a constructor, where you initialize state and bind methods. This phase is called the mounting phase, and the constructor is the first method called when a component is created.

2. static getDerivedStateFromProps:

This static method is called before every render and is used to update the state based on changes in props. It’s a rare method to use, but when needed, it can be a powerful tool.

3. render:

The render method is where the UI is constructed. React determines what changes are needed in the DOM, and this method returns the JSX that represents the component’s view.

4. componentDidMount:

After the render, componentDidMount is called. It’s the ideal place to perform side effects such as data fetching, subscriptions, or manually changing the DOM.

Growing and Evolving: Updating

5. static getDerivedStateFromProps (Again):

This method is called again during the updating phase. It allows you to synchronize the state with changes in props.

6. shouldComponentUpdate:

Before rendering, React calls shouldComponentUpdate to determine if the component should re-render. You can optimize performance by implementing this method to avoid unnecessary renders.

7. render (Again):

The render method is called again during the updating phase, generating the updated UI.

8. componentDidUpdate:

After the component updates, componentDidUpdate is invoked. It’s useful for performing actions after the component re-renders, such as updating the DOM or fetching additional data.

The Final Act: Unmounting

9. componentWillUnmount:

When a component is removed from the DOM, component will unmount is called. It’s an opportunity to perform cleanup tasks, such as canceling network requests or clearing up subscriptions.