What is React ?

React is an open-source JavaScript library for building user interfaces (UIs). It was developed by Facebook and released in 2013. React is widely used to create interactive and dynamic web applications.

React follows a component-based architecture, where the UI is divided into reusable components. Each component manages its own state and updates the UI based on changes in that state. This approach makes it easier to build complex UIs by composing smaller, reusable components together.

One of the key features of React is its use of a virtual DOM (Document Object Model). The virtual DOM is a lightweight copy of the actual DOM, which is a representation of the web page's structure. React uses the virtual DOM to efficiently update and render only the components that have changed, instead of re-rendering the entire page. This approach improves performance and makes React applications fast and responsive

React can be used to build single-page applications (SPAs) as well as mobile applications using React Native. It has a vast ecosystem of libraries, tools, and community support, making it a popular choice for front-end development.

Syllabus

1. Introduction to React

   • What is React?
   • Why use React?
   • Setting up a development environment



2. JSX (JavaScript XML)

   • JSX syntax and usage
   • Rendering JSX elements
   • JSX expressions and components



3. Components

   • Creating functional components
   • Creating class components
   • Props and state in components
   • Component lifecycle methods



4. Rendering and JSX

   • Conditional rendering
   • List rendering
   • Fragment and key usage
   • Styling components



5. State and Lifecycle

   • State management in React
   • Handling events
   • Component lifecycle methods
   • Updating component state



6. React Router

   • Introduction to React Router
   • Setting up routes
   • Navigating between routes
   • Passing parameters to routes



7. Forms and User Input

   • Controlled and uncontrolled components
   • Handling form submission
   • Form validation
   • Handling user input

8. React Hooks

   • Introduction to hooks
   • useState hook
   • useEffect hook
   • Custom hooks



9. Context API

   • Introduction to Context API
   • Creating and consuming contexts
   • Using context in components



10. State Management (Redux, MobX, etc.)

    • Introduction to state management
    • Redux fundamentals (actions, reducers, store)
    • Integrating Redux with React
    • Alternatives to Redux (MobX, Recoil, etc.)



11. React and HTTP

    • Fetching data from an API
    • Handling asynchronous operations
    • Axios or other HTTP libraries



12. React and Testing

    • Introduction to testing in React
    • Unit testing with Jest and Enzyme
    • Testing components and hooks



13. React Best Practices and Performance Optimization

    • Code organization and project structure
    • Performance optimization techniques
    • React Developer Tools and debugging



14. React and Server-Side Rendering (SSR)

    • Introduction to SSR
    • Server-side rendering with Next.js

History

• 2011: Facebook starts using a JavaScript library called XHP for building UI components. XHP was based on PHP, and its syntax resembled HTML.




• 2011: Jordan Walke, a software engineer at Facebook, builds a prototype of React called "FaxJS" during a Hackathon event. FaxJS aimed to solve the performance issues Facebook was facing with XHP.




• 2013: React is officially released by Facebook as an open-source project at the JSConf US conference. The initial version of React focused on solving the challenge of efficiently updating complex UI components.




• 2015: React Native is introduced, allowing developers to build native mobile applications using React. It leverages the power of React's component model and declarative syntax to create cross-platform mobile apps.

• 2016: React Fiber, a reimplementation of React's core algorithm, is announced. React Fiber improves the performance and enables new features like asynchronous rendering and better support for concurrent updates.




• 2018: React Hooks are introduced, providing a new way to write stateful components and manage state without using class components. Hooks simplify component logic and encourage reusability.




• 2020: React 17 is released with some notable changes. It introduces React's new JSX Transform, which removes the need to import the React object in each file using JSX. Additionally, it improves error handling and paves the way for smoother upgrades in the future.




• 2021: Concurrent Mode, a new feature in React, is introduced as an experimental API. Concurrent Mode aims to improve the responsiveness and user experience of React applications by enabling more efficient rendering and better scheduling of updates.