Register to get access to free programming courses with interactive exercises

useRef Hook JS: React Hooks

Usually we work with the useRef() hook to use DOM elements in useEffect() or event handlers:

const Input = () => {
  // null – initial value
  const inputEl = useRef(null);

  const onButtonClick = () => {
    // `current` points to the mounted `input` element `input`

  return (
      <input ref={inputEl} type="text" />
      <button onClick={onButtonClick}>Focus</button>

The value inside inputEl appears after we mount the component but before we call the hooks. Don't forget to set the ref attribute for the desired element when you do so.

Another way to use useRef() is to store data between component calls. This hook returns a regular object with the current property inside.

The only difference between this object and the manually created { current: ... } is that the hook returns the same object every time we call the component. In its behavior, useRef() is similar to using a regular property inside a class component (this.someproperty).

Below is an example of how you can save the previous state using useRef():

See the Pen use_ref by Hexlet (@hexlet) on CodePen.

Recommended materials

  1. Using the useRef Hook
  2. Measure a Dom node

Hexlet Experts

Are there any more questions? Ask them in the Discussion section.

The Hexlet support team or other students will answer you.

About Hexlet learning process

For full access to the course you need a professional subscription.

A professional subscription will give you full access to all Hexlet courses, projects and lifetime access to the theory of lessons learned. You can cancel your subscription at any time.

Get access
hours of theory

Sign up

Programming courses for beginners and experienced developers. Start training for free

  • 130 courses, 2000+ hours of theory
  • 1000 practical tasks in a browser
  • 360 000 students
By sending this form, you agree to our Personal Policy and Service Conditions

Our graduates work in companies:

<span class="translation_missing" title="translation missing:">Bookmate</span>
<span class="translation_missing" title="translation missing:">Healthsamurai</span>
<span class="translation_missing" title="translation missing:">Dualboot</span>
<span class="translation_missing" title="translation missing:">Abbyy</span>
Suggested learning programs
Development of front-end components for web applications
10 months
from scratch
Start at any time

Use Hexlet to the fullest extent!

  • Ask questions about the lesson
  • Test your knowledge in quizzes
  • Practice in your browser
  • Track your progress

Sign up or sign in

By sending this form, you agree to our Personal Policy and Service Conditions
Toto Image

Ask questions if you want to discuss a theory or an exercise. Hexlet Support Team and experienced community members can help find answers and solve a problem.