- Answer: Imagine you're playing a game of "Spot the Differences" between two similar pictures. The virtual DOM is like a cheat sheet that tells you exactly which parts have changed, so you don't have to search the entire pictures. React uses this cheat sheet to update only the necessary elements in the real DOM, making the game (and your app) much faster!
2. How do you handle state management in React? Explain the difference between local state and global state.
- Answer: Think of state as a backpack. Local state is like keeping your personal belongings in your own backpack, easily accessible and private. Global state is like a community backpack shared by everyone, where you put items that need to be accessed and modified by different components. It's like a team effort to keep things organized and synchronized!
3. What is the purpose of React hooks? Can you give an example of how you have used hooks in your projects?
- Answer: React hooks are like magical tools that make functional components more powerful. It's like having a Swiss Army knife for building UIs! For example, I've used the useState hook to create a "Dark Mode" toggle button in one of my projects. It allowed me to toggle between light and dark themes, making the user experience more customizable and fun!
4. Describe the component lifecycle methods in React. Which methods are deprecated in React 16 and above?
- Answer: Think of component lifecycle as a superhero's journey. They have a beginning (mounting), middle (updating), and end (unmounting). In React 16 and above, some older superheroes like componentWillMount and componentWillReceiveProps retired, but new heroes like componentDidMount and componentDidUpdate stepped in with enhanced powers to ensure smooth and heroic app performances!
- Answer: It's like passing a secret message to your teammate during a game. You whisper the message (data) to them, and they use it to make their next move. In React, the parent component passes the message (data) to the child component using props. It's a fantastic way to share information and cooperate between components, just like a winning game strategy!
- Answer: React components are like building blocks for your app, just like LEGO pieces! They are reusable, self-contained modules that encapsulate functionality and user interface. Components help in creating a modular, maintainable, and scalable app by breaking it down into smaller, manageable pieces.
- Answer: JSX is like a magic spell that combines HTML-like syntax with JavaScript powers! It allows you to write HTML-like code within your JavaScript files. It's like mixing the best of both worlds, making it easier to create dynamic and interactive user interfaces in React. With JSX, you can seamlessly embed JavaScript expressions and create stunning UIs.
8. What is the purpose of React Router and how does it enable client-side routing in a React application?
- Answer: Think of React Router as a navigation system for your app, like a GPS! It helps you navigate between different components and pages without refreshing the entire app. Just like a GPS guides you to different destinations, React Router enables smooth and seamless transitions between different views in a React application.
- Answer: Handling forms in React is like orchestrating a symphony! Controlled components are like playing each musical note with precision, where the form values are controlled by React state. Uncontrolled components are like playing freestyle, where the form values are handled by the DOM directly. Both approaches have their uses, depending on the complexity and requirements of the form.
- Answer: React context is like a magical backpack that allows you to pass data through the component tree without explicitly passing props at each level. It's like sharing a secret power with specific components or even the entire app! React context is useful when you have data that needs to be accessible by multiple components, avoiding prop drilling and making the code more maintainable.