title: Check if Object contains string in TypeScript
body: <p>In my <code>TypeScript</code> I have this class:</p>
  
  <pre><code>export class PhoneBookPerson {
      Email: string;
      Name: string;
      Phonenumber: string;
      ProfileImg: string;
      Department: string;
      JobTitle: string;
      Username: string;
  }
  </code></pre>
  
  <p>I'm wondering how can I check if any of the properties contains a specific value.</p>
  
  <pre><code>let $SearchTerm = target.val();
  function RetrievedUsers(sender: any, args: any) {
      for (let i = 0; i &lt; users.get_count(); i++) {
          let user = users.getItemAtIndex(i);
  
          let person = new PhoneBookPerson();
          person.Name = user.get_loginName();
          person.Email = user.get_email();
          person.Username = user.get_loginName();
          person.JobTitle = user.get_title();
          &lt;-- search of person contains value from $SearchTerm                        
          usermatch.push(person);
      }
  }
  </code></pre>