title: Where to save global settings in Angular 4
body: <p>In Angular (Type Script) there are many config files. Which is the right one to save a global setting?</p>
  
  <p>For example, when I am calling API from local then my <code>rootUrl</code> is <code>localhost:42000</code> but when I switch on production it should be <code>http:www.someting.com</code>. </p>
  
  <p>I want to save this <code>rootUrl</code> in some global place so if I switch on production then I only have to change in this <code>rootUrl</code>.</p>
  
  <p>Please suggest where should I save these global settings, same as web.config in Asp.Net. </p>