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Anil
Anil

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How to work virtual DOM in React || DOM

In React, the Virtual DOM is a concept that allows React to efficiently update the browser's DOM by first updating a virtual representation of it. This virtual representation is a lightweight copy of the actual DOM. When changes are made to the virtual DOM, React compares it with the previous version (using a process called "reconciliation") and computes the minimum number of updates needed to reflect those changes in the real DOM. This approach results in faster rendering and better performance.

Here's an example to illustrate how the Virtual DOM works in React:

Suppose you have the following React component:

import React, { useState } from 'react';

const Counter = () => {
  const [count, setCount] = useState(0);

  const increment = () => {
    setCount(count + 1);
  };

  return (
    <div>
      <h2>Counter</h2>
      <p>Count: {count}</p>
      <button onClick={increment}>Increment</button>
    </div>
  );
};

export default Counter;

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In this component:

  1. We have a Counter functional component that displays a count value and a button to increment the count.
  2. The count state is managed using the useState hook.
  3. When the button is clicked, the increment function is called, which updates the count state.
  4. Now, let's see how React handles the updates using theVirtual DOM:
  5. Initially, React renders the Counter component and creates a virtual representation of the DOM based on its JSX structure.
  6. When the button is clicked, the increment function is called, updating the count state.
  7. React then re-renders the Counter component.
  8. Instead of directly updating the real DOM, React compares the new virtual DOM with the previous one.
  9. React identifies the differences (in this case, the updated count value) and computes the minimal set of changes needed to reflect those differences in the real DOM.
  10. Finally, React updates the real DOM with the minimal changes.
  11. This process allows React to optimize rendering performance by minimizing unnecessary updates to the DOM, resulting in a smoother user experience. The Virtual DOM acts as a reconciliation layer between the developer's desired UI state and the actual DOM, making React applications more efficient and performant.

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