How to Build a Dynamic Filtering System using React

 

Introduction:

React is one of the most popular front-end libraries used by developers to build user interfaces. Its popularity has led to a high demand for React developers in the job market. To stand out in a competitive field, it's essential to be prepared for React interviews. Here are five challenging React interview questions that even senior front-end developers might find tricky to answer.

Question 1: Explain the difference between state and props in React.

State: State is a built-in feature in React components used to store mutable data. It is managed internally by the component and can be updated using the setState method. State is local and can only be accessed within the component where it is defined.

Props: Props (short for properties) are read-only data passed from parent to child components. They are used to customize a component's behavior or appearance. Unlike state, props are immutable and cannot be changed within the component.

Question 2: How does React handle data binding?

React uses a unidirectional data flow, which means data flows in one direction from parent to child components. When the state of a component changes, React automatically re-renders the component and its children to reflect the updated state. This approach ensures that the UI remains in sync with the underlying data.

Question 3: What is JSX in React?

JSX (JavaScript XML) is a syntax extension for JavaScript that allows developers to write HTML-like code within their JavaScript files. JSX makes it easier to create and manipulate DOM elements in React applications. It also allows developers to use JavaScript expressions within their markup, enabling dynamic content rendering.

Question 4: How can you optimize React performance?

To optimize React performance, developers can follow several best practices:

• Use the virtual DOM to minimize DOM manipulation and improve rendering performance.
• Memoize expensive operations or computations using React.memo or useMemo to prevent unnecessary re-renders.
• Split components into smaller, more manageable pieces to improve code maintainability and performance.
• Use the shouldComponentUpdate lifecycle method or React.memo to prevent unnecessary re-renders of components.

Question 5: What are hooks in React? How do they differ from class components?

Hooks are a new addition in React 16.8 that allow developers to use state and other React features without writing class components. Hooks are functions that enable developers to "hook into" React state and lifecycle features from functional components. They provide a more concise and readable way to work with stateful logic in React applications compared to class components.

Conclusion:

These five React interview questions are designed to test your understanding of React concepts and best practices. By familiarizing yourself with these questions and their answers, you can confidently tackle React interviews and demonstrate your expertise in front-end development.

FAQs:

1. What is the main difference between React class components and functional components with hooks?
2. How can you pass data from a parent component to a child component in React?
3. What is the significance of the key prop in React lists?
4. How does React handle routing in single-page applications?
5. Can you explain the concept of React context and when it should be used?