how virtual dom performed in vuejs

 In Vue.js, the Virtual DOM (Document Object Model) is a programming concept that is used to improve the performance of web applications. It is a lightweight, in-memory representation of the actual DOM that allows Vue.js to efficiently update the user interface in response to changes in the underlying data.

The Virtual DOM works by creating a tree of JavaScript objects that represent the structure of the actual DOM. When changes are made to the data in the Vue.js application, the Virtual DOM is updated accordingly. The Virtual DOM then compares the updated Virtual DOM with the previous Virtual DOM to determine which parts of the actual DOM need to be updated.

By using the Virtual DOM, Vue.js is able to reduce the number of expensive DOM operations that are required to update the user interface. Instead of re-rendering the entire DOM each time there is a change, Vue.js only updates the specific parts of the DOM that have changed. This results in a faster and more efficient user interface.

Another advantage of the Virtual DOM is that it makes it easier to write reactive components. Reactive components are components that automatically update in response to changes in the underlying data. With the Virtual DOM, Vue.js is able to efficiently track changes in the data and update the user interface accordingly.

Overall, the Virtual DOM is a key part of Vue.js's performance optimization strategy. By using the Virtual DOM, Vue.js is able to provide a fast and responsive user interface, even for complex web applications with large amounts of data.

In Vue.js, the Virtual DOM is implemented using a library called "snabbdom". Snabbdom is a fast and lightweight virtual DOM library that allows Vue.js to efficiently update the user interface in response to changes in the underlying data.

When changes are made to the data in a Vue.js application, the framework first creates a new virtual DOM tree based on the updated data. This new virtual DOM tree is then compared with the previous virtual DOM tree to determine which parts of the actual DOM need to be updated.

Snabbdom uses a technique called "patching" to update the actual DOM. Patching involves comparing the new virtual DOM tree with the previous virtual DOM tree, and then applying only the necessary changes to the actual DOM.

Patching is a much more efficient technique than re-rendering the entire DOM each time there is a change. By only updating the necessary parts of the DOM, Vue.js is able to provide a faster and more efficient user interface.

In addition to patching, Snabbdom also uses a technique called "keyed updates" to further optimize performance. Keyed updates allow Vue.js to efficiently update lists and other dynamic elements in the user interface.

Overall, the implementation of the Virtual DOM in Vue.js is highly optimized for performance. By using a fast and lightweight virtual DOM library like Snabbdom, and by using techniques like patching and keyed updates, Vue.js is able to provide a fast and responsive user interface even for complex web applications with large amounts of data.