React Interview QuestionWhat is the virtual DOM? How does react use the virtual DOMto render the UI?
By using the virtual DOM and performing efficient updates to the real DOM 2 player games, React minimizes the number of actual manipulations and improves performance. It allows React to batch updates, optimize rendering, and provide a smooth and responsive user interface.
Sample code
import React, { useState } from 'react';const Counter = () => { const [count, setCount] = useState(0); const handleClick = () => { setCount(count + 1); }; return ( <div> <p>Count: {count}</p> <button onClick={handleClick}>Increment</button> </div> );};export default Counter;
import React, { useState } from 'react';
const Counter = () => {
const [count, setCount] = useState(0);
const handleClick = () => {
setCount(count + 1);
};
return (
<div>
<p>Count: {count}</p>
<button onClick={handleClick}>Increment</button>
</div>
);
export default Counter;
When a component’s state or props change in React, the Virtual DOM is updated with the new values. React then compares the new Virtual DOM with the previous one to identify the differences (also known as “diffing”). Once the differences are identified, React updates only the parts of the actual DOM that need to be changed, rather than updating the entire DOM.
This process of comparing the Virtual DOM with the previous Virtual DOM and updating only the parts of the actual DOM that need to be changed is known as “reconciliation”. By using the Virtual DOM and reconciliation process, React is able to update the UI efficiently and quickly.
The Virtual DOM is a representation of the actual Document Object Model (DOM) used by web browsers to render web pages. In React, the Virtual DOM is an abstraction layer on top of the actual DOM, which allows for efficient updates to the UI.
The virtual DOM is like a replica of a real DOM which is used by React to build the UI. Later this virtual DOM is applied to the real DOM and UI is displayed.