React Hooks - useRef

What is useRef?

The useRef hook in React is tailored for working with DOM elements and mutable values within functional components. Its key advantage is that it avoids unnecessary re-renders, boosting performance.

A major use case for useRef is obtaining direct references to DOM elements, which is useful for imperative operations like focusing inputs or working with external libraries. It also stores values across renders without causing re-renders, serving as a lightweight alternative to the useState.

const ref = useRef(initialValue);

// examples
const counts = useRef(0);
const myValue = useRef(null);

The difference between with and without useRef

• without useRef - when clicking the button, the console will show 2 messages, You clicked x times! and re-rendering
• with useRef - - when clicking the button, the console will show 1 message, You clicked x times! only

Example code

import { useState, useEffect, useRef } from "react";

export default function App() {
	const [count, setCount] = useState(0);

	function handleClick() {
		setCount((prevCount) => prevCount + 1);
		console.log(`You clicked ${count} times!`);
	}

	useEffect(() => {
		console.log("re-rendering");
	}, [count]);

	// let ref = useRef(0);

	// function handleClick() {
	// 	ref.current++;
	// 	console.log(`You clicked ${ref.current} times!`);
	// }

	// useEffect(() => {
	// 	console.log("re-rendering")
	// }, [ref])

	return <button onClick={handleClick}>Click me!</button>;
}

Recap

The useRef hook is a tool in React for managing mutable values and interacting with the DOM within functional components. It shares similarities with useCallback and useMemo in that it prevents unnecessary re-renders, contributing to better performance.

Resources

• useRef - React Docs
• BUILD a React Timer with useRef | React Hooks useRef Tutorial by Dave Gray

Thank you!

Thank you for your time and for reading this!