What is react.js
React.js is a popular JavaScript library used for building user interfaces (UIs) for web applications. It was developed by Facebook and is currently maintained by Facebook and a community of developers. React.js is often used in combination with other libraries and frameworks, such as Redux and Next.js, to create scalable and maintainable applications.
Here are some key features of React.js:
Declarative programming: React.js allows you to describe the desired UI state and React.js takes care of updating the UI when the state changes. This makes it easier to reason about the code and reduces the risk of bugs.
Component-based architecture: React.js is built around the concept of components, which are reusable building blocks for UIs. Components can be composed to create more complex UIs, and they can be reused across different parts of an application.
Virtual DOM: React.js uses a virtual DOM to optimize UI updates. When the state of a component changes, React.js updates the virtual DOM and compares it with the real DOM. It then updates only the parts of the real DOM that need to be changed, which makes the UI updates faster and more efficient.
JSX: React.js uses a syntax extension called JSX, which allows you to write HTML-like code in your JavaScript files. This makes it easier to write and read code and helps to reduce the risk of syntax errors.
Unidirectional data flow: React.js follows a unidirectional data flow, which means that the data flows in a single direction, from the parent component to the child components. This makes it easier to reason about the data flow and reduces the risk of bugs.
React.js has a large and active community of developers, and there are many resources available for learning React.js, including the official documentation, tutorials, and online courses. React.js is a powerful tool for building modern web applications and is used by many companies, including Facebook, Netflix, and Airbnb.