The useState hook was created to help us to store data and update the UI all the times that the data changes. But, every time the state changes, it causes a re-render on your app and this could be a problem.

Let's take a look on the code below

You might be thinking: “It works, there's nothing wrong, right?” - The answer is: no.

The onChange function will set a state every time the user presses a key on keyboard. It means the app will re-render every time the user types a letter.

And as we can see, our app is re-rendering unnecessary. 👇🏽

*So, we gonna fix that using the useRef hook.

Why?

First: the useRef allow us to get the input value without setting a state every time the user types a letter.

Second: We gonna use the useRef because we don't need to update the UI. If wee need to update UI, we must be using useState.

As you can see, we don't need to set a new state on the onChange event and our application just render one time, like the picture below:

“But Douglas, the app is rendering twice 😭*”* - Yes, the React Strict mode is enabled and it renders twice just to detect any problem in the app. It only runs on debug mode, so in production will gonna be safety 🙂

So, it works! Your app is happy. Now we have the entire input value without rendering so many times.

Bye 🙂