What is React
React is a free and open-source JavaScript library for building user interfaces. It's primarily focused on the view layer of an application, meaning it helps you create the interactive and dynamic parts that users see and interact with. Here are some key points about React:
Components
React's fundamental building blocks are components. These are reusable pieces of code that represent a small UI element, like a button, a form, or a section of a page.
Each component has its own state and logic, making it modular and self-contained.
You can combine components to build complex user interfaces.
JSX:
React uses JSX, a syntax extension to JavaScript that lets you write HTML-like structures within your code. This makes it easier to visualize and write the UI.
JSX is not actual HTML, but it gets transformed into regular JavaScript objects before execution.
Virtual DOM:
React uses a virtual DOM, which is an in-memory representation of the actual DOM.
When changes are made to the state of a component, React efficiently updates the virtual DOM first.
Then, it calculates the minimal set of changes needed in the real DOM, leading to more performant updates.
Benefits
Reusable components: Saves time and effort by writing components once and using them multiple times.
Declarative programming: Focuses on describing what the UI should look like, not how to manipulate it.
Efficient updates: Virtual DOM minimizes unnecessary DOM manipulations, leading to smoother performance.
Large community and ecosystem: Many libraries, tools, and resources available for React development.
Common uses
- Building single-page applications (SPAs)
- Developing mobile apps with React Native
- Creating interactive web interfaces
- Building reusable UI components