text: import React, { Component } from 'react'
  import ReactDOM from 'react-dom'
  import { BrowserRouter, Route, Switch } from 'react-router-dom'
  // import Header from './Header'
  import Login from './Login'
  import ArticleIndex from './ArticleIndex'
  import ArticleCreate from './ArticleCreate'
  import ArticleShow from './ArticleShow'
  import ArticleEdit from './ArticleEdit'
   
  class App extends Component {
      render () {
          return (
              <BrowserRouter>
                  <div>
                      {/*} <Header /> */}
                      <Switch>
                          <Route exact path='/' component={Login}/>
                          <Route exact path='/app' component={ArticleIndex}/>
                          <Route exact path='/create' component={ArticleCreate} />
                          <Route path='/article/edit/:id' component={ArticleEdit} />
                          <Route path='/article/:id' component={ArticleShow} />
                      </Switch>
                  </div>
              </BrowserRouter>
          )
      }
  }
   
  ReactDOM.render(<App />, document.getElementById('app'))