Every question is hand-checked, every answer comes with an explanation, and your progress builds into a clear picture of where you stand.
Every React question shows its code before you answer, so you are reading real React, not a description of it.
Once you attempt a question you get the reasoning, not just a tick. That matters most on React, where hook rules, stale closures inside effects, key-based reconciliation, when memo actually helps, and how server components change where code runs.
Progress is tracked per topic across the 42 React topics, so revision points at the gaps instead of the whole list.
536 React questions right now: 120 easy, 218 medium and 198 hard. That number is read straight from the question table when this page is built, so it is never a rounded marketing figure.
No. Every React question, including its code snippet, its difficulty and its topic, is readable without signing in. You need a free account only to submit an answer, see which option is correct, and read the worked explanation. We keep it that way so the platform stays honest about what you actually got right.
Hook rules, stale closures inside effects, key-based reconciliation, when memo actually helps, and how server components change where code runs.
42 distinct topics are tagged on the React questions, including useEffect dependency arrays, function components, what JSX is, embedding expressions, custom hooks, reconciliation diffing. The topic labels come from the questions themselves, so the list matches what you will actually be asked.
Yes. Reading is free and unlimited. A free account unlocks answering, explanations and progress tracking. Pro (₹199 per month) adds AI explanations and AI-graded guesstimates on top; it is not needed to practise React MCQs.
Frontend and full-stack roles, plus React Native mobile teams that share the same mental model.
These are 12 of the 536 React questions in the library, pulled live from the question table. The snippet, the difficulty and the topic are all here. The answer options and the explanation are not. Those need a free account.
Hook rules, stale closures inside effects, key-based reconciliation, when memo actually helps, and how server components change where code runs.
// this has nothing to do with question, it's a test question
const Abc = () => {
const [a, v] = useState("abc");
return (
<div>
new abc
dkkdkd
<span>
Nice working
</span>
</div>
)
}function Hi({name}){return <p>Hi {name}</p>} <Hi name="Alice"/>// legacy pattern
const [snap, setSnap] = useState(store.getSnapshot());
useEffect(() => {
const unsub = store.subscribe(() => setSnap(store.getSnapshot()));
return unsub;
}, []);const ThemeContext = React.createContext('light');
function App() {
return <Child />; // no Provider anywhere
}
function Child() {
const theme = useContext(ThemeContext);
console.log(theme);
return null;
}<label htmlFor="email">Email</label>
<input id="email" />const [searchParams, setSearchParams] = useSearchParams();
const goToPage = (n) =>
setSearchParams({ page: String(n) });useEffect(() => {
const sub = subscribe(id);
return () => {
console.log('cleanup');
sub.unsubscribe();
};
}, [id]);createBrowserRouter([
{
path: '/',
element: <Root/>, // renders <Outlet/>
errorElement: <RootError/>,
children: [
{ path: 'reports', element: <Reports/>, loader: reportsLoader }, // loader throws
],
},
]);<p>{count}</p><button>+</button>function handleChange(e) {
setText(e.target.value); // urgent
startTransition(() => {
setFilter(e.target.value); // transition (low priority)
});
}function usePrevious(value) {
const ref = useRef();
useEffect(() => {
ref.current = value;
});
return ref.current;
}We keep the correct answer, the explanation and the scoring behind sign-in so the platform stays honest, which is why the correct option and the worked explanation for every React question stay behind a free account. Signing in is free and takes a few seconds.
Frontend and full-stack roles, plus React Native mobile teams that share the same mental model.