Question 1

How do you handle side effects in functional components?

Accepted Answer

**Target Audience:** Frontend engineers preparing for React interviews — assumes basic familiarity with Hooks. **Difficulty:** Medium > **How to read this doc:** Every concept is explained in plain language first, then tagged with 📌 Interview term: — the exact vocabulary an interviewer expects. Every ordering and lifecycle claim below was produced by actually running React 19.2.8 in a real DOM (jsdom) in this repo, not described from documentation. ## 1. Why This Even Matters — A

Question 2

What are the advantages of using React over plain JavaScript?

Accepted Answer

**Target Audience:** Engineers preparing for React interviews — assumes JavaScript and DOM basics. **Difficulty:** Easy to Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. This is a trade-off question, so the answer below deliberately includes the costs — an interviewer is often testing whether you can argue against your own tool. ## 1. Why This Even Matters — A Story First Picture a whiteboard tracking a foot

Question 3

What is React and its main features?

Accepted Answer

**Target Audience:** Anyone preparing for a React interview — assumes no prior React knowledge. **Difficulty:** Easy > **How to read this doc:** Every concept is explained in plain language first. Right after, you will see a callout like 📌 Interview term: — the exact vocabulary an interviewer expects. The object-shape claims below were produced by running React 19.2.8 in this repo. ## 1. Why This Even Matters — A Story First Imagine decorating a room by giving instructions over

Question 4

What is `create-react-app` and when would you use it?

Accepted Answer

**Target Audience:** Engineers preparing for React interviews — assumes you have started a React project before. **Difficulty:** Easy > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The deprecation status below was checked against the React team announcement rather than recalled — this is a topic where an out-of-date answer is very visible, so the source is cited inline. ## 1. Why This Even Matters — A Story First <

Question 5

How do you handle asynchronous operations in React functional components?

Accepted Answer

**Target Audience:** Engineers preparing for React interviews — assumes useEffect and promises. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. The race-condition outcome in section 4 and React warning text in section 3 were both produced by running the code on React 19.2.8, not described from memory. ## 1. Why This Even Matters — A Story First You order a taxi, change your mind,

Question 6

How do you fetch data in React?

Accepted Answer

**Target Audience:** Engineers preparing for React interviews — assumes useEffect. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. This doc is the decision landscape; async operations covers the mechanics and race conditions, and

Question 7

How do you interact with external APIs in React?

Accepted Answer

**Target Audience:** Engineers preparing for React interviews — assumes fetch and hooks. **Difficulty:** Medium > **How to read this doc:** Concepts are explained in plain language first, then tagged with 📌 Interview term:. This doc is about **integration architecture**; how to fetch data in React covers choosing a fetching strategy, and

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