title: Unable to use Arrays on Typescript 3.1 with Angular 7
body: <p>I am trying to use a types array for an application using Typescript 3.1.1 Angular 7.. There seems to be something I am missing. So I tried a simple string array and even that doesn't seem to work for me.. Not sure what I am missing..</p>
  
  <pre><code>let array: string[] = [];
  
  array.push("test"); //&lt;--- doesn't work. :(
  </code></pre>
  
  <p>This results in the exception:</p>
  
  <pre><code>[ts] Property 'push' does not exist on type '{}'.
  </code></pre>