React/ReactJS 19 - Professional Interview Questions 2025

Congratulations!  You've found the most efficient, profitable, and up-to-date Q&A resource online for learning React!

Thousands of other engineers have learned React, and you can too.

React was released by Facebook's web development team in 2013 as a view library. React is one of the best choices for building modern web applications. React has a slim API, a robust and evolving ecosystem, and a great community.

React has been the most popular Javascript library of the last five years, and the job market is still hotter than ever.  Companies large and small can't hire engineers who understand React and Redux fast enough, and salaries for engineers are at an all-time high.  It's a great time to learn React!

React.js is THE most popular JavaScript library you can use and learn these days to build modern, reactive user interfaces for the web.

This Q&A course is fully up-to-date with React 19 (the latest version of React)!

The test covers:

* VirtualDOM

* React app creation

* Create React components

* React lifecycle definition

* React state management definition

* React component properties

* Communication between React components

* Event management

* DOM manipulation

* Data propagation

* Hooks

* State in a function

* useState and useEffect

* Error Boundaries

* TypeScript use with React

* React patterns

* Lifting State Up