React Virtual Dom

React virtual dom

Created By: chatGPT

The Virtual DOM is a concept implemented by React to enhance the performance of web applications. Instead of directly manipulating the real DOM, React creates a lightweight representation of it in memory. This allows React to identify changes and update only the necessary parts of the DOM.

const virtualDOM = {
    tag: 'div',
    children: [
        { tag: 'h1', content: 'Hello, World!' },
        { tag: 'p', content: 'This is a paragraph.' }
    ]
};

When a component's state or props change, React first updates the Virtual DOM. After the update, it compares the new Virtual DOM with the previous version using a process called reconciliation. This process efficiently determines what has changed.

function render(virtualDOM) {
    const element = document.createElement(virtualDOM.tag);
    virtualDOM.children.forEach(child => {
        if (typeof child === 'string') {
            element.appendChild(document.createTextNode(child));
        } else {
            element.appendChild(render(child));
        }
    });
    return element;
}

Once React identifies the changes, it then updates only the affected parts of the real DOM. This selective updating process minimizes performance bottlenecks typically associated with direct DOM manipulation, leading to a smoother user experience.

function updateRealDOM(virtualDOM, realDOM) {
    if (virtualDOM.tag !== realDOM.tag) {
        const newRealDOM = render(virtualDOM);
        realDOM.parentNode.replaceChild(newRealDOM, realDOM);
    } else {
        // update attributes and children
        const children = virtualDOM.children;
        // logic to update attributes and child nodes
    }
}

In summary, the Virtual DOM acts as an intermediary between React and the real DOM, minimizing updates and improving performance. This functionality is a key reason why React applications tend to be faster and more efficient than conventional approaches.

ReactDOM.render(
    render(virtualDOM),
    document.getElementById('root')
);