React Router overview

Introduction

React Router helps you change pages in a React app without reloading the whole page. It makes your app feel faster and smoother.

You want to build a website with multiple pages like Home, About, and Contact.

You want users to navigate inside your app without waiting for full page reloads.

You want to show different content based on the URL in the browser.

You want to keep the app state while moving between pages.

You want to create links that users can bookmark or share.

Syntax

React

import { BrowserRouter, Routes, Route, Link } from 'react-router-dom';

function App() {
  return (
    <BrowserRouter>
      <nav>
        <Link to="/">Home</Link>
        <Link to="/about">About</Link>
      </nav>
      <Routes>
        <Route path="/" element={<Home />} />
        <Route path="/about" element={<About />} />
      </Routes>
    </BrowserRouter>
  );
}

BrowserRouter wraps your app to enable routing.

Routes contains all your route definitions.

Examples

Basic setup with two routes: Home and About.

React

import { BrowserRouter, Routes, Route } from 'react-router-dom';

<BrowserRouter>
  <Routes>
    <Route path="/" element={<Home />} />
    <Route path="/about" element={<About />} />
  </Routes>
</BrowserRouter>

Link component changes the URL without reloading the page.

React

<Link to="/about">Go to About</Link>

Route with a dynamic parameter to show different profiles.

React

<Route path="/profile/:id" element={<Profile />} />

Sample Program

This React app uses React Router to switch between Home, About, and a dynamic Profile page. The navigation links let you move between pages without reloading.

React

import React from 'react';
import { createRoot } from 'react-dom/client';
import { BrowserRouter, Routes, Route, Link, useParams } from 'react-router-dom';

function Home() {
  return <h2>Home Page</h2>;
}

function About() {
  return <h2>About Page</h2>;
}

function Profile() {
  const { id } = useParams();
  return <h2>Profile Page for user {id}</h2>;
}

function App() {
  return (
    <BrowserRouter>
      <nav aria-label="Main navigation">
        <Link to="/" style={{ marginRight: '1rem' }}>Home</Link>
        <Link to="/about" style={{ marginRight: '1rem' }}>About</Link>
        <Link to="/profile/42">Profile 42</Link>
      </nav>
      <Routes>
        <Route path="/" element={<Home />} />
        <Route path="/about" element={<About />} />
        <Route path="/profile/:id" element={<Profile />} />
      </Routes>
    </BrowserRouter>
  );
}

const container = document.getElementById('root');
const root = createRoot(container);
root.render(<App />);

Important Notes

Always wrap your app in BrowserRouter to enable routing.

Use Link instead of <a> tags to avoid full page reloads.

Dynamic routes let you show different content based on URL parts.

Summary

React Router lets you build multi-page apps without reloading the browser.

Use BrowserRouter, Routes, and Route to define pages.

Link changes pages smoothly and updates the URL.

Practice

1. What is the main purpose of React Router in a React application?

easy

A. To style React components with CSS

B. To create multiple pages without reloading the browser

C. To manage state across components

D. To fetch data from APIs

Solution

1. Step 1: Understand React Router's role

   React Router helps build apps with multiple pages by changing views without full page reloads.

2. Step 2: Compare with other options

   Styling, state management, and data fetching are handled by other tools, not React Router.

3. Final Answer:

   To create multiple pages without reloading the browser -> Option B

4. Quick Check:

   React Router = multi-page navigation without reload [OK]

Hint: React Router = multi-page navigation without full reload [OK]

Common Mistakes:

• Confusing React Router with CSS or styling tools
• Thinking React Router manages data fetching
• Assuming React Router handles state management

2. Which of the following is the correct way to wrap your app with React Router for browser-based routing?

easy

A. <BrowserRouter>...</BrowserRouter>

B. <Link>...</Link>

C. <Route>...</Route>

D. <Router>...</Router>

Solution

1. Step 1: Identify the main router component

   For browser history routing, React Router uses BrowserRouter to wrap the app.

2. Step 2: Understand other components

   Route defines pages, Link creates navigation links, and Router alone is not a valid component.

3. Final Answer:

   <BrowserRouter>...</BrowserRouter> -> Option A

4. Quick Check:

   BrowserRouter wraps app for browser routing [OK]

Hint: Wrap app with <BrowserRouter> for browser routing [OK]

Common Mistakes:

• Using <Router> instead of <BrowserRouter>
• Confusing <Route> with the router wrapper
• Wrapping app with <Link> which is for navigation

3. Given this React Router setup, what will be rendered when the URL path is /about?

import { BrowserRouter, Routes, Route } from 'react-router-dom';

function App() {
  return (
    <BrowserRouter>
      <Routes>
        <Route path='/' element=<Home /> />
        <Route path='/about' element=<About /> />
      </Routes>
    </BrowserRouter>
  );
}

medium

A. The component

B. Nothing renders because of missing default route

C. Both and components

D. The component

Solution

1. Step 1: Match URL path with Route path

   The URL /about matches the route with path='/about', so <About /> renders.

2. Step 2: Understand route exclusivity

   Only the matching route's element renders; <Home /> renders only at /.

3. Final Answer:

   The <About /> component -> Option D

4. Quick Check:

   URL '/about' renders About component [OK]

Hint: URL path matches Route path exactly to render component [OK]

Common Mistakes:

• Thinking both components render simultaneously
• Assuming missing default route breaks rendering
• Confusing '/' path with '/about'

4. Identify the error in this React Router code snippet:

import { BrowserRouter, Routes, Route } from 'react-router-dom';

function App() {
  return (
    <BrowserRouter>
      <Route path='/' element=<Home /> />
      <Routes>
        <Route path='/about' element=<About /> />
      </Routes>
    </BrowserRouter>
  );
}

medium

A. <Route> must be inside <Routes>

B. Missing closing tag for <BrowserRouter>

C. The <Route> for '/' should not have an element prop

D. Cannot use <Route> and <Routes> together

Solution

1. Step 1: Check component nesting rules

   In React Router, all <Route> components must be children of <Routes>.

2. Step 2: Identify incorrect placement

   The <Route path='/' ... /> is outside <Routes>, which is invalid.

3. Final Answer:

   <Route> must be inside <Routes> -> Option A

4. Quick Check:

   Routes wrap Route components [OK]

Hint: Always put <Route> inside <Routes> component [OK]

Common Mistakes:

• Placing <Route> outside <Routes>
• Thinking <Route> can be used alone
• Confusing element prop usage

5. You want to create a navigation menu that changes the URL without reloading the page. Which React Router component should you use, and why? Choose the best option.

hard

A. Use <Route> because it defines the navigation links

B. Use <a> tags because they are standard HTML links

C. Use <Link> because it updates the URL and renders the new page without reload

D. Use <BrowserRouter> because it creates the navigation menu

Solution

1. Step 1: Identify component for navigation links

   <Link> is designed to change the URL and render new pages without reloading.

2. Step 2: Compare with other options

   <a> causes full page reload, <Route> defines pages, and <BrowserRouter> wraps the app but does not create links.

3. Final Answer:

   Use <Link> because it updates the URL and renders the new page without reload -> Option C

4. Quick Check:

   Use Link for smooth navigation without reload [OK]

Hint: Use <Link> for navigation to avoid full page reload [OK]

Common Mistakes:

• Using <a> tags causing full reload
• Confusing <Route> with navigation links
• Thinking <BrowserRouter> creates menus