title: How to get the previous page URL in angular 5
body: <p>I'm working with Angular 5 app and I need to know how to get the last URL to place it as a link to my back button. I found this <code>location.back()</code> but what I need the last url as a string. How could I get the string that generates <code>location.back()</code>?</p>
  
  <p>Many Thanks!</p>