Create a Single Page Application (SPA) in React App with proper navigation.

Sure, I can help you with that!

To create a Single Page Application with proper navigation in React, you can follow these steps:

1. Set up a new React project using create-react-app or any other preferred method.
2. Install the react-router-dom package using npm or yarn.
3. Create a new file called App.js and import the necessary components from react-router-dom.
4. Define the routes for your application using the Route component. You can use the Switch component to ensure that only one route is rendered at a time.
5. Add a Navbar component to your application to provide navigation between the routes. You can use the NavLink component to style the active link.
6. Add a default route to handle 404 errors.

Here's an example of what your App.js file might look like:

import React from 'react';
import { BrowserRouter as Router, Route, Switch, NavLink } from 'react-router-dom';

import Home from './components/Home';
import About from './components/About';
import Contact from './components/Contact';
import NotFound from './components/NotFound';

function App() {
  return (
    <Router>
      <div>
        <nav>
          <ul>
            <li>
              <NavLink exact activeClassName="active" to="/">Home</NavLink>
            </li>
            <li>
              <NavLink activeClassName="active" to="/about">About</NavLink>
            </li>
            <li>
              <NavLink activeClassName="active" to="/contact">Contact</NavLink>
            </li>
          </ul>
        </nav>

        <Switch>
          <Route exact path="/" component={Home} />
          <Route path="/about" component={About} />
          <Route path="/contact" component={Contact} />
          <Route component={NotFound} />
        </Switch>
      </div>
    </Router>
  );
}

export default App;

In this example, we've defined three routes for the Home, About, and Contact components, and a default route for any other paths. We've also added a Navbar component to provide navigation between the routes.

I hope that helps! Let me know if you have any further questions.