title: Should one use const when declaring an arrow function in React class
body: <p>Inside a react class component, should one use a const/let to declare an arrow function, or they should be emmited:</p>
  
  <pre><code>  class ReactComp extend Component {
        const sayHello = () =&gt; {
            return 'Hello';
        }
        sayBye = () =&gt; {
            return 'Hello';
        }
        render() {
            &lt;div&gt;
              {this.sayHello}
              {this.sayBye}
            &lt;/div&gt;
        }
    }
  </code></pre>
  
  <p>In this example, is sayBye declared correctly? (Without a const)</p>
  
  <p>In addition, why outside the class, such a declaration does not work?</p>
  
  <pre><code>  class ReactComp extend Component {
  
        render() {
            &lt;div&gt;
              {sayHello}
              {sayBye}
            &lt;/div&gt;
        }
    }
    const sayHello = () =&gt; {
        return 'Hello';
    }
    sayBye = () =&gt; {
        return 'Hello';
    }
  </code></pre>
  
  <p>This will return an exception: Uncaught ReferenceError: sayBye is not defined</p>
  
  <p>Thanks a lot!</p>