What is the virtual DOM in Vue.js?

by

In Vue.js, the virtual DOM is a tree-like data structure or a collection of JavaScript objects that represents DOM nodes. Vue.js manage the nodes of the virtual DOM, and that should be rendered on the page. These objects are called “virtual nodes” or VNodes.

In Vue.js, the virtual DOM is a representation of the actual DOM (Document Object Model) in JavaScript objects. It is an abstraction of the HTML DOM and serves as an intermediary layer between the Vue components and the actual browser DOM.

Here’s a more detailed breakdown of the virtual DOM in Vue.js:

  1. Efficiency: Vue.js uses a virtual DOM to optimize the process of updating the actual DOM. Instead of directly manipulating the DOM every time there is a change in the data, Vue.js updates the virtual DOM first. This allows Vue.js to batch updates and perform them efficiently.
  2. Diffing Algorithm: After updating the virtual DOM, Vue.js performs a process known as “diffing” to identify the minimal number of changes needed to update the actual DOM. This process compares the updated virtual DOM with the previous state of the virtual DOM to determine the changes that need to be applied to the actual DOM.
  3. Reduced Browser Manipulation: Manipulating the actual DOM can be expensive in terms of performance, especially when dealing with complex and dynamic web applications. By using a virtual DOM, Vue.js minimizes direct manipulation of the DOM, resulting in better performance and improved user experience.
  4. Reactivity: The virtual DOM plays a crucial role in Vue.js’ reactivity system. When data changes in a Vue component, Vue.js efficiently updates the virtual DOM and applies the necessary changes to the actual DOM, ensuring that the UI reflects the latest state of the application.

In summary, the virtual DOM in Vue.js is a key feature that improves performance, facilitates efficient updates to the actual DOM, and enhances the reactivity of Vue.js applications.