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Mounting, Updating and Unmounting Lifecycle Methods in React

Introduction to React
What is React? Advantages of React JSX syntax Setting up the development environment
Components and Props
Components in React Functional Components Class Components Props PropTypes and defaultProps Component composition
State and Lifecycle Methods
State in React setState method Lifecycle Methods in Class Components Conditional Rendering based on the state
Handling Events
Event handling in React Binding Event Handlers Passing Arguments to Event Handlers Conditional Event Handling
Forms and User Input
Forms in React Controlled Components Uncontrolled Components Form Validation
Lists and Keys
Rendering Lists in React Keys Extracting Components with Keys
Components Lifecycle
Understanding Components Lifecycle Mounting, Updating and Unmounting Lifecycle Methods
Working with APIs
Making HTTP Requests with Axios Handling Responses with Promises Asyncawait syntax for making API calls
React Router
What is React Router? Installation Configuring Routes Navigating between pages using Link and NavLink components
Redux State Management
What is Redux Three principles of Redux Redux Store, Actions, and Reducers ReactRedux integration
Styling React Applications
Styling in React Inline styles CSS Modules Styled Components
Testing React Applications
Testing Fundamentals Testing React Components Integration Testing Using Jest and React Testing Library
Deployment and Optimization
Deployment options for React applications Performance Optimization Code Splitting React Lazy and Suspense
Next Steps
Advanced Topics Resources for continued learning Conclusion

Mounting, Updating and Unmounting Lifecycle Methods

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#description

In React, components have a set of methods that are invoked automatically at specific stages of a component's lifecycle. These methods are known as lifecycle methods. There are three main stages of a component's lifecycle: Mounting, Updating, and Unmounting.

  1. Mounting: Mounting is the stage in which a component is created and inserted into the DOM.

When a component is first inserted into the DOM, the following methods are called in the specified order:
  • constructor(): This is the first method called when a component is created. It is used to initialize state, bind methods, and set up any other necessary configurations.
  • getDerivedStateFromProps(): This method is called right after the constructor and before the render method. It receives props as an argument and returns an object that represents changes to the state.
  • render(): This method is required and returns the React element that will be inserted into the DOM.
  • componentDidMount(): This method is called after the component is rendered and inserted into the DOM. It is used to perform any necessary actions such as setting up event listeners or starting timers.
  1. Updating: Updating is the stage in which a component receives new props or state and re-renders. This stage can happen multiple times throughout a component's lifetime.

The following methods are called during the updating stage:
  • getDerivedStateFromProps(): This method is called again with the new props and state and returns an object that represents changes to the state.
  • shouldComponentUpdate(): This method is called before rendering and returns a boolean value that determines whether the component should update or not.
  • render(): This method is called again and returns the updated React element.
  • componentDidUpdate(): This method is called after the component has been updated in the DOM. It is used to perform any necessary actions such as fetching new data or re-initializing state.
  1. Unmounting: Unmounting is the stage in which a component is removed from the DOM.

The following method is called during the unmounting stage:
  • componentWillUnmount(): This method is called right before the component is removed from the DOM. It is used to perform any necessary actions such as cleaning up event listeners or stopping timers.

By understanding these lifecycle methods, you can effectively manage the state and behavior of your React components throughout their lifetime.

March 25, 2023

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