title: how do I check if a property exists in an object?
body: <p>Apologize. I'm fairly certain this is a rather novice question; however, here it goes! Thanks for any hints in advance :)</p>
  
  <p>I have the below function in my app, and running the app now throws the error "TypeError: parameters.includes is not a function." What does this error mean? Does the if statement require a function? How should I set up this conditional?</p>
  
  <pre><code>function handleApiAiAction(sender, action, responseText, contexts, parameters, response) {
      switch (action) {
          case "job-search":
              console.log(parameters);
              if (parameters.includes("quickreply")) {
                  console.log("it worked");
              } else {
                  let replies = response.result.fulfillment.messages[0].replies;
                  let title = response.result.fulfillment.messages[0].title;
                  sendQuickReply(sender, title, replies);
                  console.log("it didn't work");
              }
              break;
          default:
              //unhandled action, just send back the text
              sendTextMessage(sender, responseText);
      }
  }
  </code></pre>
  
  <p>console.log('parameters') gives me:</p>
  
  <pre><code>{ quickreply: 'quickreply' }
  </code></pre>
  
  <p>[some edits :)]</p>