router-example.jsx

// you can define router
// and add a switch with all routes as a child of a "Main layout component" called app

import React from 'react';
import { render } from 'react-dom';
import createHistory from 'history/createBrowserHistory';
import { Router, Route, Redirect, Switch } from 'react-router-dom';

const history = createHistory();

const routes = (
  <Router history={history}>
    <App>
      <Switch>
        <Route exact path="/" component={Home} />
        <Route exact path="/post" component={PostList} />
        <Route path="/showpost/:slug" component={ShowPost} />
        <Route path="/page/:slug" component={ShowPage} />
        <Route path="/login" component={Login} />
        <Route path="/register" component={Register} />
        <Route path="/forgotpassword" component={Forgot} />
        <Route path="/password/reset/:token" component={Reset} />
        <Route path="/logout" component={Logout} />
        <Route path="/user" component={User} />
        <Route path="/saveorder" render={()=><SaveOrder data={this.state.data}/>} />
      </Switch>
    </App>
  </Router>
);

// and then in your app.js component 

const App = props => (
  <div>
   <Header />
   <Menu />
   <div>
    {props.children}
   </div>
  </div>
);

export default App;