Top React Interview Questions [2024]
React is an open-source Javascript library developers use to build user interfaces (UIs) for web and mobile applications. Creating React applications usually requires the use of additional libraries and functionality, and so interviewing React candidates commonly consists of basic and advanced questions to assess technical ability. We sourced these questions from the React community based on developers’ own interview experience and what our clients found important to ask. Could you use help hiring React developers? Scalable Path’s experienced Talent Acquisition team can help.
React Interview Questions
These are the types of questions typically asked during React interviews. We created them to help you test your understanding of the popular programming language, or guide your initial technical screening with React candidates.
Write ES6+ code logic for myFunction and explain the concepts used and their purpose: console.log( myFunction (3)(4)(5) ) outputs 12. View Answer
Explain the JSX transformation process and how browsers render JSX.View Answer
How do you incorporate custom JSX transformations into your build process?View Answer
Write JSX code and explain how a parent component could reference a DOM element from it's child component (hint: use Ref, non-hook version)View Answer
Can you extend the Child component to show how the “Ref Forwarding” concept works?View Answer
What are the three special rules of writing any redux reducer function?View Answer
What are the reasons to use react hooks? View Answer
What are the lifecycle phases of a component (React V16.4+) ?View Answer
Can you explain the updating phase and its important lifecycle methods?View Answer
When do components re-render?View Answer
How can you avoid unwanted re-rendering of child components?View Answer
What are some ways of styling a React project?View Answer
What is utility-first CSS and when is it preferred over UI-kit based libraries?View Answer
How should you organize a new React project structure?View Answer
Several components in a React app need to reflect/sync with the same changing data. What steps would you take to design them?View Answer
What is a render prop? Explain its use cases and caveats.View Answer
Which is the closest to the Gang of Four's Decorator pattern in React (or) what is a HOC?View Answer
What are the applications of HOC?View Answer
What are the caveats of HOC?View Answer
What are Props Collection and Props Getter patterns?View Answer
When is Props Getter preferred over the other?View Answer
What is route-based code splitting and how is it achieved in React?View Answer
What are the testing libraries you have used in a React project?View Answer
How does Shallow Renderer work?View Answer
Enzyme vs React-testing LibraryView Answer
This list isn't exhaustive, and interviewing typically includes an assessment of soft skills and technical ability through a take-home assignment or live coding exercise. You can learn more about hiring here.
