React Interview Preparation: Best Questions, Best Answers, and Sample Code 1. What are the differences between functional and class components in React? Answer : Functional components are simpler and mainly focus on rendering UI, while class components provide more powerful features like state management and lifecycle methods . In recent versions of React, hooks ( useState ,  useEffect ) enable functional components to use state and lifecycle features without needing to be classes. // Functional Component function FunctionalComponent(props) {     const [count, setCount] = useState(0);     return (         <div>             <p>Count: {count}</p>             <button onClick={() => setCount(count + 1)}>Increment</button>         </div>     ); } // Class Component class ClassComponent extends React.Component { ...

As a React developer, you’ll eventually experience the urge to take that next large step into a senior role. Many of us stay stuck as a junior or mid-level developer, even as we get more experienced.  Here are some very common interview questions you may be asked while interviewing for a senior -level position as a React developer. 1. Can you describe a situation where you had to optimize a React application to improve its performance? How did you go about doing this? ⨠ As a candidate for a senior React developer position, you will be expected at times to know how to optimize a React app for better performance. Understanding React’s lifecycle and hooks can help with this. Some ways of optimizing a React app’s performance can include Avoiding unnecessary rerenders Using a UID (unique identifier) when rendering lists Using hooks such as useMemo and useCallback to memoize expense functions Mounting checks. 2. How do you handle state management in a large React application? ⨠   T...