title: Error : property does not exist on type
body: <p>I am a newbie in coding world and learning angular 4. In my application,
  I have 3 classes <code>MyGlobalObject.ts</code>, <code>globalservice.service.ts</code> and <code>history.ts</code>. </p>
  
  <p>I am trying to fetch the data from a JSON file (API) having the values in <code>history.ts</code>, but in <code>globalservice</code> class, I am getting an error saying property <code>startdateandtime</code> does not exist on type <code>History[]</code>. </p>
  
  <p>But the property do exist in the history.ts as shown in the above images having code.</p>
  
  <p><code>myglobalobject.ts:</code></p>
  
  <p><img src="https://i.stack.imgur.com/otPmR.png" alt="CodeScreenshot#1"></p>
  
  <p><img src="https://i.stack.imgur.com/zaj7w.png" alt="CodeScreenshot#2"></p>
  
  <hr>
  
  <p><code>History.ts:</code></p>
  
  <p><img src="https://i.stack.imgur.com/wZvI0.png" alt="CodeScreenshot#3"></p>
  
  <hr>
  
  <p><code>globalservice.service.ts:</code></p>
  
  <p><img src="https://i.stack.imgur.com/kuPBD.png" alt="CodeScreenshot#4"></p>