How React Works Internally
React is a JavaScript library for building user interfaces. Here's a simplified overview of how it works internally:
Virtual DOM
React uses a virtual DOM (a lightweight in-memory representation of the real DOM) to optimize rendering. When the state of the application changes, React updates the virtual DOM, and then efficiently updates the real DOM by comparing the two and only making the necessary changes.
JSX
JSX is a syntax extension for JavaScript that allows you to write HTML-like code in your JavaScript files. When you use JSX, React compiles it into JavaScript functions that return React elements.
React Elements
React elements are the building blocks of React applications. They are objects that describe what should be rendered to the DOM. When you create a React element, you are creating a new object that represents a component.
Component Tree
React components are organized into a tree-like structure. Each component can contain other components, and the tree is traversed when rendering the application.
Rendering
When the state of the application changes, React updates the virtual DOM and then efficiently updates the real DOM by comparing the two and only making the necessary changes.
Event Handling
React provides a way to handle events, such as clicks and keyboard input, by attaching event handlers to components. When an event occurs, React calls the event handler function, which can then update the state of the application.
State and Props
React components have two main properties: state and props. State is an object that stores the component's internal data, while props are immutable values passed from a parent component.
Lifecycle Methods
React components have several lifecycle methods that are called at different points during the component's life cycle, such as when it is mounted or unmounted.
Conclusion
In summary, React works internally by using a virtual DOM to optimize rendering, JSX to write HTML-like code, React elements to describe what should be rendered, a component tree to organize components, and event handling and state management to interact with the application.