Casting document.getElementById to access files in TypeScript
<p>I am very new to angularjs. I wasn't able to find the solution online. 
I would like to read the text from a file. I was trying to follow this example. 
<a href="https://stackoverflow.com/questions/26165919/filereader-not-loading-file-properly-using-angularjs">FileReader not loading file properly using AngularJS</a></p>

<p>However, since I'm using TypeScript, I receive this error for this line</p>

<pre><code>document.getElementById('fileInput').files[0];
</code></pre>

<p>Error:
Property 'files' does not exist on type 'HTMLElement'.</p>

<p>Please suggest me how I can cast to use the files. </p>