title: React: is not defined no-undef
body: <p>When I refresh the error message in clearAll() is:</p>
  
  <p>./src/App.js</p>
  
  <p>Line 22:  'notes' is not defined  no-undef</p>
  
  <p>Line 23:  'notes' is not defined  no-undef</p>
  
  <p>How do I define the the properties to use></p>
  
  <pre><code>import React, { Component } from 'react';
  import Route from 'react-router-dom';
  import './App.css';
  import Header from './components/Header';
  import Router from './components/Router';
  import Home from '.Home';
  import AddNote from '/AddNote';
  import EditNote from '/EditNote';
  
  
  class App extends React.Component {
  
  constructor(props) {
      super(props);
      this.state = {
          note: "",
          notes: []
      };
  }
  
  clearAll() {
      notes.length = 0;
      notes = [];
  }
  </code></pre>