title: Why use back tick with ${ in const in typescript
body: <p>I am going through the angular turorial and I see the below</p>
  
  <p><a href="https://angular.io/tutorial/toh-pt6" rel="noreferrer">https://angular.io/tutorial/toh-pt6</a></p>
  
  <pre><code>const url = `${this.heroesUrl}/${hero.id}`;
  </code></pre>
  
  <p>Can someone explain why I need to use ` before ${ ? Since this is typescript and similar to javascript can I not use </p>
  
  <pre><code> this.heroesUrl + "/" + hero.id 
  </code></pre>
  
  <p>Why do I need to use back tick and the ${ operation? </p>