React.js is extremely efficient: React.js creates its own virtual DOM where your components actually live. This approach gives you enormous flexibility and amazing gain in performance. React.js also calculates what are the changes needed to be made in DOM. This process of React.js avoids expensive DOM operations and make updates in a very client manner.
It gives you out-of-the-box developer tools: When you start your journey with React.js, do not forget to install official React.js chrome extension. It makes debugging your application much easier. After you install the extension, you will have a direct look into the virtual DOM as if you were browsing a regular DOM tree in the elements panel. Isn’t it pretty amazing!
UI Test Cases: It is extremely easy to write UI test cases because the virtual DOM system implemented entirely in JS.