Overview

Handling routing in a React application is fundamental for building single-page applications (SPAs). It involves managing navigation from one component to another without refreshing the page. This enhances the user experience by making applications faster and more responsive. React Router is the standard library for routing in React, offering dynamic routing capabilities that sync with your UI.

Key Concepts

1. React Router: A library that enables the implementation of dynamic routing in a web app.
2. Route Matching: Determines which route should render based on the URL's pathname.
3. Navigation: Using Link or NavLink components to navigate between pages without a full page reload.

Common Interview Questions

Basic Level

1. What is React Router and why is it used?
2. How do you create basic routes in a React application using React Router?

Intermediate Level

3. How does React Router implement dynamic routing?

Advanced Level

4. Can you explain the difference between <BrowserRouter> and <HashRouter> and when you might use one over the other?

Detailed Answers

1. What is React Router and why is it used?

Answer: React Router is a standard library for routing in React applications. It enables the navigation among views of various components in a React Application, without refreshing the page. This is a key part of building single-page applications (SPAs). It keeps the UI in sync with the URL, making it possible to bookmark and share URLs to specific parts of the application.

Key Points:
- Enables the creation of single-page applications.
- Keeps the UI and URL in sync.
- Improves user experience by enabling fast and responsive page transitions.

Example:

// React Router is not relevant to C#, and as such, a C# example is not applicable.

2. How do you create basic routes in a React application using React Router?

Answer: Basic routes in React can be created using the BrowserRouter and Route components from the react-router-dom package. Each Route component specifies a path and the component to render when the path matches the current URL.

Key Points:
- Use BrowserRouter as the router wrapper.
- Define routes with the Route component.
- Match the current URL's path to a component.

Example:

// React Router is not relevant to C#, and as such, a C# example is not applicable.

3. How does React Router implement dynamic routing?

Answer: React Router implements dynamic routing by allowing routes to be defined as part of the component hierarchy. It matches the URL's pathname to the path defined in a Route component and renders the component if the path matches. Unlike traditional routing, where routes are predefined and unchanging, dynamic routing adapts as the application state changes.

Key Points:
- Routes are components, making them part of the React component tree.
- Path matching is dynamic, allowing for more flexible navigation structures.
- Enables component-based routing that reacts to state changes.

Example:

// React Router is not relevant to C#, and as such, a C# example is not applicable.

4. Can you explain the difference between <BrowserRouter> and <HashRouter> and when you might use one over the other?

Answer: <BrowserRouter> and <HashRouter> are both components in React Router for handling routing, but they use different methods to keep the UI in sync with the URL.

• <BrowserRouter> uses the HTML5 history API to create real URLs. It's suitable for dynamic web applications where you want clean URLs without hashes.

• <HashRouter> uses the URL's hash portion (the part after #) to keep the UI in sync with the URL. It's useful in static websites where server configuration is not possible to rewrite requests to index.html.

Key Points:
- <BrowserRouter> for dynamic web applications with server support for clean URLs.
- <HashRouter> for static websites or when clean URLs are not necessary.
- Choose based on the server configuration and the type of URLs you want.

Example:

// React Router is not relevant to C#, and as such, a C# example is not applicable.