Category: React

  • ReactJS giving error Uncaught TypeError: Super expression must either be null or a function, not undefined

    ReactJS giving error Uncaught TypeError: Super expression must either be null or a function, not undefined If you are working with ReactJS, you might have come across the error message “Uncaught TypeError: Super expression must either be null or a function, not undefined”. This error usually occurs when you are using the extends keyword to…

  • Typescript: React event types

    Typescript: React event types When working with React and TypeScript, it’s important to understand the different event types that can be used in your components. In this blog post, we will explore the various event types available in TypeScript for handling events in React. 1. SyntheticEvent The SyntheticEvent is a cross-browser wrapper around the native…

  • Concatenating variables and strings in React

    When working with React, there may be times when you need to concatenate variables and strings to dynamically generate content. In this blog post, we will explore different ways to achieve this in React. 1. Using the + Operator One way to concatenate variables and strings in React is by using the + operator. This…

  • How to set default Checked in checkbox ReactJS?

    When working with checkboxes in ReactJS, you may come across the need to set a default checked value. In this blog post, we will explore two different solutions to achieve this. Solution 1: Using the defaultChecked attribute The simplest way to set a default checked value in a checkbox component is by using the defaultChecked…

  • How do you programmatically update query params in react-router?

    How do you programmatically update query params in react-router? If you are working with React and using react-router for routing, you might come across a situation where you need to programmatically update the query parameters in the URL. This can be useful when you want to update the URL based on user actions or when…

  • What’s the ‘@’ (at symbol) in the Redux @connect decorator?

    When working with Redux, you may have come across the @connect decorator. But what exactly does the @ symbol mean in this context? In this article, we’ll explore the purpose and usage of the @connect decorator in Redux. The @connect decorator is a shorthand syntax provided by the react-redux library, which is commonly used with…

  • React 18: Hydration failed because the initial UI does not match what was rendered on the server

    React 18: Hydration failed because the initial UI does not match what was rendered on the server If you are encountering the error message “Hydration failed because the initial UI does not match what was rendered on the server” when using React 18, don’t worry, you’re not alone. This error typically occurs when the initial…

  • Deprecation notice: ReactDOM.render is no longer supported in React 18

    Deprecation notice: ReactDOM.render is no longer supported in React 18 If you are a React developer, you might have come across the deprecation notice for ReactDOM.render in React 18. This change has been introduced to improve performance and simplify the React API. In this blog post, we will discuss the deprecation of ReactDOM.render and explore…

  • forEach() in React JSX does not output any HTML

    forEach() in React JSX does not output any HTML If you are working with React JSX and using the forEach() method to iterate over an array and render HTML elements, you may have encountered a problem where no HTML is being output. This can be frustrating, but there are a few solutions to this issue.…

  • React setState not updating state

    React setState not updating state One of the most common issues that developers face while working with React is when the setState method does not update the state as expected. This can be frustrating and can lead to unexpected behavior in your application. In this blog post, we will explore some possible reasons for this…