Understanding React Diffing: How It Works to Efficiently Update the UI

React is a popular JavaScript library used for building user interfaces. One of the key features that makes React efficient is its ability to efficiently update the DOM. React accomplishes this through a process called „diffing“. In this article, we will explore how React diffing works in detail.

What is Diffing?

Diffing is the process of comparing two sets of data to determine the differences between them. In the context of React, diffing is used to determine the differences between the current state of the UI and the new state. Once the differences have been identified, React updates the DOM to reflect the new state.

The Virtual DOM

Before we dive into how diffing works, we need to understand the concept of the virtual DOM. The virtual DOM is a lightweight representation of the actual DOM. It is a JavaScript object that contains all the necessary information to recreate the DOM tree. When the state of the UI changes, React creates a new virtual DOM and compares it to the previous one. This is where diffing comes in.