4 Best Practices for ReactJs Developers to Handle Error Messages

Are you one of the professional ReactJs developers or just kick-starting your career? Regardless of your experience level, you may face React error messages at some point during the development process.

Even a highly-proficient developer may end upwriting codes that lead to error messages. After all, mistakes are bound to happen. But what’s more important is how to handle these issues.

Traditionally, ReactJs developers used to follow a tedious approach to address error messages. For example, when they encounter the errors, the next step was searching them on Google. Finally, they fixed them as per the instructions provided by an expert online.

Thanks to continuous advancements in technology, we have hassle-free solutions to development errors. However, looking for solutions every time you find errors in your code is a time-consuming process. To sort things out, our experts made a list of the   common error messages and solutions to fix them. But before we start, you need to know how to display a React error message.

  • What does it take to display an error message in React?

    It is essential to show React error messages accurately. After all, it plays a crucial role in error handling. Until these errors are visible, you cannot resolve them. One of the easiest ways to display them is to have a state for storing them.

    For example, use this state:

    errorMessage: const [errorMessage, setErrorMessage] =

    When a React developer, freelancer or on-site developer comes across an error message, they update it to errorMessagestate: setErrorMessage('Example error message!');

    After this, the developer uses React’s conditional rendering to show the error message. For this, they can write an inline conditional statement, such as:

    {errorMessage&& (
    <p className="error"> {errorMessage} </p>

    In the end, they will have a button that displays the React error message with one click.

    With this, you just learned how to display an error message in React application. Now, it is the right time to discover the typical error messages and the solutions to address them efficiently.

  • Tips for ReactJs developers to handle error messages
  1. Each child in a list must have a unique Key prop

    ReactJs development services providers take the item of an array and leverage a component for rendering. It is done according to the item’s content. Luckily, we have JSX to embed the logic into the component with an Array.map function. As a result, it sets out the intended components from the callback.

    But during this process, you may meet with a warning in your browser console. The caption is, “Each child in a list should have a unique Key prop.” If you are a novice ReactJs developer, you will need time to learn to add a unique “Key” prop to every child. Until then, you can use this solution to address the error.


    The warning suggests that there should be a Key prop to each element of the JSX. To do so, you need to meet the following requirements:

    • The Key should be a number or a string.
    • It should be unique to each item.
    • It should represent the item in the list throughout renders.

    If you fail to stick to these requirements, your ReactJs app will not crash, but you may face unexpected performance and behavior issues. React lets you discover which Key has the problem. Depending on this, you can fix the error. If you wish to become one of the highly proficient ReactJs Developers, master error fixing practices.

  2. Avoid using Array index in Keys

    Another warning related to Keys is preventing using an array index. Such errors can occur when a developer becomes habitual of using the Key prop in each child list.

    In some cases, your data might not have a unique identifier. So, using the index in the list is an easy solution. But using an array index as a Key prop is not reliable because it fails to represent an individual item across renders.

    For example, you have a list of items that users use to interact. If they remove the second item, it will not affect the underlying DOM structure of the first one, as evidenced by its Key, which remains at 0. The same applies to the third and beyond. The Key prop from other items will undergo modifications, as they depend on the array index.

    However, ReactJs will compute the structure again, assuming that items have changed. As a result, it will affect performance adversely while causing inconsistent states. How do top ReactJs developers handle this error? Keep reading for a solution.


    Before you fix this, it is essential to know that Keys need not to be identifiers. Any Key will work as long as it is unique and represents the DOM structure.

  3. Do not call React Hooks conditionally

    As a React developer, freelancer or on-site professional, you can optimize code in various ways. But you should know that you can execute specific code in the code branches when necessary. For instance, it is useful when you come across time-consuming or resource-heavy code. Consequently, it boosts performance significantly.

    During the implementation of this optimization technique, you may run into a warning. It says – you should not call the React Hooks conditionally. Instead, it must be called in the same order in all component renders.

    Why is it necessary?

    React has an internal order that calls Hooks to watch over the underlying states. Also, it preserves these states between renders.

    What will happen if you mismanage this order? In this case, React may mismatch the state with the Hook. It may result in bugs in the application.


    The best way competent ReactJs developers address this error message is by calling React Hooks at the top-grade components. Plus, it should be unconditional.

  4. An infinite loop of re-renders

    Managing infinite loops is a nightmare for every developer. As a professional delivering ReactJs development services, you cannot escape this. But you have an advantage that React identifies the instance of too many re-renders and notifies you about the same. Hence, you can fix it before the application becomes unresponsive.


    According to the warning, your component stimulates several re-renders, which is problematic. You face this issue when a component queues countless state updates in a short span. Here are some reasons that cause infinite loops, such as:

    • If you perform state updates in the render directly.
    • If you fail to provide the correct callback to an event handler.

    So, whenever you receive this warning, the first thing to check is if these two aspects are working fine. That is what an experienced and skilled ReactJs developer would do.

In closing

When developing ReactJs applications, you can come across the error messages we discussed above. The errors are inevitable, but if you know what to do, you can fix these issues and restore your application. On the other hand, neglecting these warnings can cost you big time. Also, enterprises hire ReactJs developers with proficiency in all aspects of web development like coding, deploying, debugging, etc.

So, whether you are an on-site or freelance React developer, you should understand these error messages. After all, they are a crucial part of the React app development process.

If you want to read more topics like this to improve your skills, contact SoftProdigy. We have a team of expert ReactJs developers and on-site programmers who are committed to delivering top-notch services. Learn and grow your skills with us!


  1. Is ReactJs popular?

ReactJs is one of the most popular front-end development frameworks for its exceptional flexibility and simplicity. There are more than 13,000 React developers, and nearly 94,000 sites are built with React.

  1. Which leading brands use ReactJs?

ReactJs is a choice for both start-ups and well-established companies, thanks to its incredible features. Some of the tech giants that use React are Netflix, Facebook, Uber, Amazon, Airbnb, Instagram, etc.