Frontend undefined

Naming things is hard.

I eventually called this blog "Frontend undefined" because we keep coming up with new ways to build on the web. And because we still run into cannot read property of undefined errors.

Prabashwara Seneviratne

Prabashwara Seneviratne

Author. Lead frontend developer.

Every month I share useful tips for working with React and in-depth reviews of frontend libraries and tools in a monthly post.

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A brief history of state management libraries for React
Building a sample React app
Why React Context is not great for global state
Right to left (RTL) layouts


A summary of libraries that are commonly used with React


How to fix a 404 Page Not Found error when using React router on Netlify
How to build a Vite project for production
How to set up a React project from scratch with Webpack and Babel
How to build a Create React App (CRA) project for production
How to fix a 404 Not Found error when refreshing a React app
How to fix 404 errors when using React Router with Nginx
How to use Docker to setup a React development environment
How to use Docker Compose to host a React web app
How to dockerize a React web app


What does Webpack and Babel do in a React project?
How to set up a backend for a React app?
Which frontend framework should you learn as a beginner?
Is it a library or a framework?
Do you need to know Javascript to learn React?
How much Javascript do you need to know to learn React?
How to pick a frontend library or tool?

React Demystified

Is your React useState hook not updating state immediately? Here's how to fix it
Why multiple calls to set state with the React useState hook don't work
console.log printing twice in React? That is React StrictMode in action


Basic webpack config for a React project
Sample Dockerfile for hosting a React web app


Code is for humans
The way we code changes: 8 years of frontend libraries
It takes time