How to use the React Interview Flashcards
- 1. Choose topicsPick one topic or all of them, a round size, and whether to skip cards you already know.
- 2. Flip and gradeRead the question, answer aloud, then reveal the answer and mark it known or still learning.
- 3. Review your resultsMissed cards come back later in the round. At the end see your score by topic and download the cards to revise.
What the deck covers
The deck covers modern React with function components and hooks, which is what nearly every current React interview expects. The 23 cards are grouped into 11 topics: Basics, Lists, Hooks, State, Context, Rendering, Routing, Performance, Patterns, Data, Errors. Answers are short on purpose: one or two sentences you can say out loud, which you then back up with an example from your own projects.
A card from the deck
Q: When does useEffect run?
A: After render. With no dependency array it runs after every render; with [] only after the first; with [a, b] when a or b changes. A returned function cleans up before the next run and on unmount.
A good follow-up is to explain what happens without the cleanup function, such as a subscription or timer that keeps running after the component unmounts.
How to study with it
- Build a tiny component for each hook card; you'll remember it far better.
- Be ready to explain one performance problem you fixed, not just the definitions.
- In the React deck, cards you mark "still learning" come back three cards later in the same round, and the results screen lists them so you can download a revision sheet.
More questions from this deck
Other React questions you'll meet include:
- What is JSX?
- Why do list items need keys?
- What are the rules of hooks?
- Why is setCount(count + 1) twice only +1?
- When does a component re-render?
Frequently asked questions
Are class components covered?
Only where relevant, such as error boundaries, which still need a class.
Which React version?
React 18 and 19, including Strict Mode's double effects in development.
Are the React interview flashcards free?
Yes. You can flip through every card of the React interview flashcards without signing up. When you open your results for the first time, we ask once for your name and WhatsApp number; after that the React interview flashcards and every other Uncodemy tool open straight away.