Understanding useRef React Hook

Have you wondered or gotten confused as to what useRef React Hook is? I would want to think that it's out of curiosity, you got here. If so or otherwise, you are welcome as we embark on a little ride in understanding what the React useRef hook is.

I was confused and wanted to know more about it, did some research and decided to pen down my thoughts and how I understood them, in the hopes that someone gets to learn too.

In this article, we will look at the definition of useRef, comparison to states and props, common use cases, how best to use it, and debugging issues associated with useRef. Now, let's look into the definition.

What is useRef in React?

useRef is a hook in React that allows you to access the value of a DOM element or a component instance. The useRef hook returns a mutable object with a single property, .current, which you can use to store and retrieve a value. Unlike a state, the value stored in a ref does not cause a re-render when it changes, making it useful for storing values that don't need to trigger a re-render, such as references to DOM elements, timeouts, intervals, and more.

The useRef hook is a way to persist values between renders and is particularly useful for cases where you need to access the value of an element or component after it has been rendered. For example, you might use useRef to store a reference to an input field so you can programmatically change its value or focus it later on.

However, the useRef hook is a powerful tool for working with React, and understanding its use cases and best practices is essential for writing efficient and effective code in React. Let's look at the common use cases for useRef.

Common use cases for useRef

useRef is a versatile hook that can be used in a variety of different ways in React. Here are some common use cases for useRef:

  1. DOM references: One of the most common use cases for useRef is to store references to DOM elements. For example, you might use useRef to store a reference to an input field, so you can programmatically change its value or focus it later on.

  2. Timers: Another common use case for useRef is to store timers, such as setTimeout or setInterval. This allows you to access the timer instance in your component's lifecycle methods, such as componentDidMount and componentWillUnmount, so you can start or stop the timer as needed.

  3. Animations: useRef can also be used to store and manipulate values used in animations, such as the position of an animated element or the progress of an animation over time.

  4. Storing values that persist between renders: useRef can be used to store values that persist between renders, such as the value of a scroll position or the height of an element. This can be useful when you need to access the value of an element or component after it has been rendered.

  5. Improving performance: Finally, useRef can be used to improve the performance of your React application by avoiding unnecessary re-renders. By using useRef to store values that don't need to trigger a re-render, you can prevent unnecessary render passes and improve the overall performance of your application.

These are just a few examples of the many use cases for useRef. Ultimately, the best use case for useRef will depend on your specific needs and requirements and understanding the strengths and limitations of useRef is key to effectively using it in your React applications. We will be looking at how to make use of useRef in our React component in the next section.

How to use useRef

Here's how to use the useRef hook in React:

  1. Import the useRef hook from the React library:
import React, { useRef } from 'react';
  1. Create a useRef hook in your component:
const myRef = useRef(initialValue);

initialValue is an optional argument that you can use to set the initial value of the .current property of the useRef object. If you don't specify an initial value, .current will be initialized as null.

  1. Set values in useRef:
myRef.current = value;

You can use the .current property of the useRef object to set or update the value stored in the ref.

  1. Access values from useRef:
const currentValue = myRef.current;

You can use the .current property of the useRef object to access the value stored in the ref.

  1. Example of useRef in a React component:

Here's an example of how you might use useRef to store a reference to an input field in a React component:

import React, { useRef, useState } from 'react';

function MyInput() {
  const inputRef = useRef(null);
  const [value, setValue] = useState('');

  function handleClick() {
    inputRef.current.focus();
  }

  return (
    <div>
      <input ref={inputRef} value={value} onChange={e => setValue(e.target.value)} />
      <button onClick={handleClick}>Focus Input</button>
    </div>
  );
}

In this example, we use useRef to store a reference to the input field in the inputRef variable. We then use the ref attribute to associate the inputRef ref with the input field. In the handleClick function, we use the .current property of inputRef to focus the input field.

Overall, useRef is a flexible and powerful hook that can be used in a variety of different ways in React. By understanding how to use useRef, you can improve the performance and functionality of your React applications. So what are the best practices for using useRef? We will be looking into that in our next section.

Best Practices for using React useRef Hook

Here are some best practices for using the useRef hook in React:

  1. Use useRef to store values that persist between renders: One of the main strengths of useRef is that it allows you to store values that persist between renders. This can be especially useful when you need to access a value after it has been rendered, such as the height of an element or the value of a timer.

  2. Avoid using useRef for values that should trigger re-renders: Because useRef values persist between renders, it's best to avoid using useRef for values that should trigger re-renders. Instead, consider using the useState hook or passing values down as props.

  3. Be mindful of performance: When used correctly, useRef can help improve the performance of your React application by avoiding unnecessary re-renders. However, if used improperly, useRef can lead to performance issues. Be mindful of the values you store in useRef and only store values that don't need to trigger re-renders.

  4. Store complex objects in useRef with caution: While it's possible to store complex objects in useRef, be cautious when doing so, as these objects will persist between renders and can lead to unexpected results if not managed correctly.

  5. Use useRef to store references to DOM elements: One of the most common use cases for useRef is to store references to DOM elements, such as input fields or elements in a canvas. This allows you to programmatically access and manipulate the element after it has been rendered.

  6. Use useRef in conjunction with other hooks: useRef can be used in conjunction with other hooks, such as useState and useEffect, to achieve more advanced functionality in your React applications.

By following these best practices, you can effectively and efficiently use the useRef hook in your React applications and that will lead us to debugging issues associated with using useRef.

Debugging Issues associated with useRef Hook

Here are some common debugging issues associated with useRef in React and how to resolve them:

  1. Incorrectly setting useRef values: One common issue with useRef is incorrectly setting its values. Make sure you are correctly accessing and updating the .current property of the useRef object.

  2. Using useRef to store values that should trigger re-renders: As mentioned in the best practices section, it's best to avoid using useRef for values that should trigger re-renders. If you find that your useRef values aren't updating as expected, it's possible that you are using useRef to store values that should be stored in useState or passed down as props.

  3. Not using useRef in conjunction with other hooks: If you are using useRef in conjunction with other hooks, such as useEffect, make sure you are using them correctly and in the right order. Improper use of hooks can cause unexpected results.

  4. Incorrectly storing complex objects in useRef: If you are storing complex objects in useRef, be cautious, and make sure you are correctly managing these objects to avoid unexpected results.

To resolve these issues, start by checking the values you are storing in useRef and make sure you are accessing and updating these values correctly. Then, consider the use case for these values and make sure you are using useRef in the most appropriate way. Finally, if you are using useRef in conjunction with other hooks, make sure you are using these hooks correctly and in the right order.

By being mindful of these debugging issues and following best practices, you can effectively and efficiently use the useRef hook in your React applications.

Here's a quick recap of what was covered in this article concerning useRef:

  • useRef is a hook in React that allows you to access the value of a DOM element or a component instance.

  • It returns a mutable object with a single property, .current which you can use to store and retrieve a value.

  • Some use cases involve improving the performance of your app, DOM references, and animations, and storing values that don't need component re-renders and values that are needed to persist between component re-renders.

  • We looked at how to use useRef

  • Some best practices when using useRef involve using useRef to store values that persist between renders, be always mindful of the performance, and using useRef in conjunction with other hooks.

For further reading on useRef, I would recommend checking out React Documentation. Thanks for reading this far. Don't forget to like and subscribe to my newsletter for more content on my blog. Also, connect with me on Twitter.