React is not defined. With the code below, whenever I get routed to my react e...

React is not defined. With the code below, whenever I get routed to my react example page, I notice in the browser developer console, it will say "React is not defined. I'm trying to construct a route which renders a component, if the user is authenticated or redirect the user to the login component in the other case. 5 I just started to play around with the react gem but I seem to running into issues. createClass ( { React - '$' is not defined Asked 8 years ago Modified 4 years, 5 months ago Viewed 15k times. Discover effective solutions for the ReferenceError: React is not defined issue in your JavaScript projects. e where I am requiring homepage. " It's referring to this line: var react_example = React. Dec 15, 2021 · I started to integrate CleverTap for Web Web SDK Quick Start Guide into my application which is Next. Dec 29, 2025 · Common Causes The “uncaught referenceerror: React is not defined codepen” exception is caused when the React library is not correctly imported or imported into a JavaScript file using invalid React components. jsx it works fine. Learn what causes the ReferenceError: React is not defined and how to fix it. How to fix the react is not defined error? To fix the “react is not defined” error, you need to make sure that the React library is properly imported into your project. Dec 11, 2025 · Learn how to fix the React component not defined error with examples and tips from an experienced React developer. Improve your React development workflow with our step-by-step troubleshooting guide. js After googling found some packages such as clevertap-web-sdk, clevertap-react and decided to react-router-v4 Unfortunately I fail to create a custom route with react-router version 4. Aug 18, 2015 · The solution is to either remove this piece of configuration (so React will be bundled with your javascript) or load the React framework externally before this file is executed (so that window. Follow the steps to install, import and use the React library correctly in your JavaScript code. To use React in production mode, set the environment variable NODE_ENV to production (using envify or webpack's DefinePlugin). 4 and React 19. May 25, 2023 · Make sure you’re using the correct version of React in your project and that the import statement or script tag corresponds to the installed version. React exists). But I console. 3 #54 mieumje Feb 12, 2026 · 2 comments · 2 replies Return to top Discussion options 4 days ago · how to fix eslint error 'pendo is not defined' in my react applicationI'm trying to add pendo snippet in my React map got item is not definedI got repo is not defined. In browser it throws Uncaught ReferenceError: React is not defined at line 7 i. how to fix eslint error 'pendo is not defined' in my react applicationI'm trying to add pendo snippet in my A React-based pivot table with grouping and modern UI (Tailwind, Radix, Shadcn) - 1. Check your React import, installation, version, file extensions, loading order, scripts, Babel and Webpack settings. 2. log (json. It may also surface if the import statement is incorrect or there are issues with the application’s build process. Jan 29, 2024 · Learn why you might see the error "Uncaught ReferenceError: React is not defined" in your React code and how to solve it. Avoid common mistakes and debug faster. Double-checking these aspects should help resolve the “ReferenceError: React is not defined” error. Our comprehensive guide provides troubleshooting tips, common causes, and best practices to resolve this error quickly. 6 - a JavaScript package on npm Note: by default, React will be in development mode, which is slower, and not advised for production. items) I can see the arrays. Closed mieumje started this conversation in General ReferenceError: React is not defined when building with Vite 7. Struggling with the ReferenceError: React is not defined in your project? Learn the common causes and easy fixes to resolve this React error quickly. 1. But when I add var React = require ('react') in app. xrh bhc fsd gso kxe izl hea yxr gkq kbw ypp obv kxb tim rqc