title: Angular 5: App http headers and url parameter
body: <p>I'm developing an angular application where authentication is being done by third party and will redirect to our app with some information in the http headers. </p>
  
  <p>Questions:</p>
  
  <ol>
  <li>How can I retrieve the information in http headers in Angular 5?</li>
  <li>How can I also retrieve url's query string in Angular 5?</li>
  </ol>
  
  <p>Thank you in advance.</p>