What is react?
React is a JS library for building user interfaces, an open source JS library that renders data into HTML views
Who developed it?
Developed by Facebook, and open source
Why learn?
- Native JavaScript operation DOM is cumbersome and inefficient (DOM-API operation UI)
- Using JavaScript to directly manipulate the DOM , the browser will do a lot of redrawing and rearranging
- Native JavaScript does not have a componentized coding scheme, and the code reuse rate is low
Features of React
- Adopt component mode and declarative coding to improve development efficiency and component reuse rate
- In React Native, React syntax can be used for mobile development (React Native is a technology that allows front-end personnel to write Android and ios applications through js)
- Use virtual DOM + excellent Diffing algorithm to minimize interaction with real DOM
JavaScript basics you need to master before learning React
- Determine the direction of this
- class (class)
- ES6 syntax specification
- npm package manager
- prototype, prototype chain
- Array Common Methods
- Modular
The basic knowledge of js to be mastered above is explained in some articles in my blog, you can search for reference.
React official website
The Chinese official website React is used to build the library of Web and native interactive interface 
https://react.docschina.org/ The next article is an explanation of jsx syntax~