Quiz for Async & Await in React

Q1: What does async/await simplify in React code?

A. Handling asynchronous operations B. Handling synchronous operations C. Rendering components D. Managing state

Q2: How do you declare an async function in React?

A. By adding the async keyword before the function B. By adding await before function C. By using useState D. By using useEffect

Q3: Where should you place await when fetching data?

A. Before the promise-based function call B. After the promise C. Inside render D. Inside JSX

Q4: Can you make the useEffect callback function async?

A. No, it should be a normal function B. Yes, always C. Only in class components D. Only if using hooks

Q5: How do you handle errors with async/await?

A. Using try-catch blocks B. Using then-catch C. Ignoring errors D. Using console.log only

Q6: What is the advantage of async/await over promises?

A. More readable and easier to debug B. Faster execution C. Uses less memory D. No need for callbacks

Q7: What happens if you forget await before a promise?

A. Promise is returned instead of resolved value B. Function fails C. Code breaks D. Error thrown immediately

Q8: How do you make an API call inside useEffect with async/await?

A. Define async function inside useEffect and call it B. Make useEffect async C. Call fetch directly in render D. Use synchronous calls

Q9: Can async functions be used outside React components?

A. Yes, anywhere JavaScript runs B. No, only in React C. Only in classes D. Only in functional components

Q10: What keyword is used to wait for a promise to resolve?

A. await B. async C. then D. catch

Q11: Is it possible to use multiple await calls sequentially?

A. Yes, await each promise in order B. No, only one await per function C. Yes, but only with Promise.all D. No, use then chaining

Q12: How do you handle multiple async operations concurrently?

A. Use Promise.all with await B. Await each separately C. Use nested try-catch D. Use useState

Q13: What should you avoid in async/await usage?

A. Blocking UI with long-running awaits B. Using try-catch C. Declaring async functions D. Returning promises

Q14: How do you debug async/await code?

A. Use debugger and console.log inside async functions B. Cannot debug async code C. Use only promises D. Use alert only

Q15: Can async/await be combined with other React hooks?

A. Yes, commonly used with useEffect and useState B. No, only standalone C. Only with class components D. Only with context

Q16: What happens if you do not handle errors in async functions?

A. Unhandled promise rejection warnings B. Code works normally C. App crashes immediately D. State updates automatically

Q17: Is async/await syntax supported in all browsers?

A. Modern browsers support it, older may need transpilation B. No browser supports it C. Only Node.js supports it D. Only Chrome supports it

Q18: Can you return data from an async function?

A. Yes, returns a promise that resolves to the data B. No, returns undefined C. Yes, but only in classes D. No, returns null

Q19: What is the main use case of async/await in React?

A. To perform asynchronous operations like API calls smoothly B. To style components C. To create components D. To handle events only